Finance calculators

Loans, valuations, business ratios and growth metrics: the maths behind money decisions.

Finance

Loans, savings, investing and everyday money maths. Every rate, term and price is an input you control, so nothing here is tied to a particular year’s figures.

All →

Loan payment & amortisationRepayment on a fixed-rate amortised loan, with a year-by-year schedule.Mortgage repaymentFull monthly housing cost: principal, interest, rates, insurance and strata.Compound interestGrowth of a lump sum plus regular contributions.Simple interestInterest charged on the original principal only.Savings goalWhat you must put away each month to hit a target.Present & future valueWhat a future sum is worth today, and vice versa.Annuity / drawdown payoutHow much a pot pays out each month until it runs dry.Retirement projectionBalance at retirement and how long it lasts.Car loanRepayment after deposit, trade-in and on-road costs.Credit card payoffHow long a balance takes to clear at a fixed payment.APR to effective rate (APY)Converts a nominal rate into the true annual yield.Inflation & purchasing powerWhat money is worth after years of price rises.Return on investmentTotal and annualised return on an investment.CAGR (compound annual growth rate)The smooth yearly rate that links a start and end value.NPV & IRRDiscounted value of a project, and the rate that makes it break even.Rule of 72Quick mental estimate of doubling time.Salary & hourly rate converterMoves between hourly, weekly, monthly and annual pay.Tip & bill splitTip amount and what each person owes.Discount & sale pricePrice after one or two discounts, and what you save.Sales tax / GST / VATAdds tax to a net price, or strips it out of a gross one.Margin & markupTurns cost and price into margin, markup and profit.Break-even pointUnits and revenue needed before a business turns a profit.Debt-to-income ratioThe ratio lenders use to size your borrowing.How much can I borrowMaximum loan a given repayment supports.Bond price & yieldPresent value of a bond’s coupons and face value.Average share cost & positionBlended entry price across several buys.Currency conversion with feesWhat you actually receive after spread and fixed fees.Dividend yieldWhat a stock pays each year as a percentage of its share price, plus yield on cost.GDP per capitaA country’s economic output divided evenly across its population.Net to gross payThe gross amount needed to leave a chosen net (take-home) figure, at a deduction rate you set.Quick Ratio CalculatorThe quick (acid-test) ratio: whether the most liquid current assets can cover current liabilities.PayPal Fees CalculatorPayPal transaction fee and the amount you actually receive, from an editable percentage and fixed fee.Money CounterTotal cash value from a count of Australian notes and coins, by denomination.COGS (Cost of Goods Sold)Cost of goods sold from beginning inventory, purchases and ending inventory.Marginal CostThe extra cost of producing more units, from total cost and quantity at two output levels.Purchasing power parity (implied rate)Implied PPP exchange rate from the price of the same basket of goods in two currencies, compared with the market rate.Deadweight Loss CalculatorEstimates deadweight loss as the area of the loss triangle from a quantity reduction and the resulting price gap.Discount Rate CalculatorSolves for the discount rate implied by a present value, a future value and a number of periods.50/30/20 budget ruleSplits after-tax income into needs, wants and savings using the 50/30/20 framework.Consumer surplusThe value buyers gain from paying less than the most they were willing to pay.Dividend incomeTotal dividend income from shares held and the dividend paid per share, plus the yield.Real estate commissionWhat an agent earns on a property sale from the sale price and the agreed commission rate.Depreciation (straight-line & declining)Annual depreciation expense and remaining book value under two common methods.Payback periodHow many years of cash flows it takes to recover an initial investment, plain and discounted.Liquidity ratios (current, quick & cash)Three views of whether current assets can cover current liabilities.Leverage & solvency ratiosHow much of a company is financed by debt, and how easily it covers interest.Working capital & turnoverThe cash cushion between current assets and current liabilities, and how hard it is working.Cash conversion cycleDays between paying for inventory and collecting cash from its sale.WACC (weighted average cost of capital)The blended return a company must earn to satisfy both lenders and shareholders.CAPM (cost of equity)The return shareholders should require, given the market risk a stock carries.Dividend discount model (Gordon growth)Values a stock as its dividends, discounted and growing forever.Dividend yield & payout ratioWhat a stock pays relative to its price, and how much of earnings that consumes.EBITDA & marginOperating profitability before interest, tax, depreciation and amortisation.Enterprise valueThe theoretical takeover price of a company: equity plus debt, minus cash on hand.Stock valuation multiples (P/E, P/B, PEG)Common price ratios used to judge whether a stock is cheap or expensive.DuPont analysis (ROE breakdown)Splits return on equity into profitability, efficiency and leverage.Sharpe ratioReturn earned above the risk-free rate, per unit of volatility taken on.Perpetuity valuePresent value of a cash flow that continues forever, flat or growing.Balloon loan paymentRegular instalment on a loan amortised over a long schedule, plus the lump sum due early.Sustainable growth rateThe fastest a company can grow using only retained profit, no new borrowing or share issues.Graham numberBenjamin Graham’s quick estimate of a fair share price from earnings and book value.Profit CalculatorTotal dollar profit from revenue minus cost of goods sold and other costs, plus the resulting margin.MPC (Marginal Propensity to Consume) CalculatorMarginal propensity to consume from a change in consumption and a change in income, plus the implied propensity to save.Liquid Net Worth CalculatorNet worth from cash and easily-sold assets only, kept separate from illiquid holdings.Price Elasticity of Demand CalculatorHow much quantity demanded responds to a price change, from an old and new price and quantity.Pro rata rentProportional rent owed for a partial period, from the full period rent and days actually occupied.Return on Equity CalculatorReturn on equity (ROE) from net income and shareholders’ equity, the profit generated per dollar of equity.Commission CalculatorCommission earned on a sale from the sale amount and commission rate, plus any base pay.Contribution Margin CalculatorContribution margin per unit and as a ratio, from selling price and variable cost, plus break-even units against fixed costs.PayPal Exchange Rate CalculatorCompares the amount PayPal converts at its own exchange rate against the underlying market rate, using an editable markup.Revenue CalculatorTotal revenue from price per unit and quantity sold, with an optional second product line added in.Marginal RevenueThe extra revenue from selling one more unit, from total revenue and quantity at two output levels.Opportunity CostThe value of the next-best alternative given up when choosing one option over another.Unemployment RateThe share of the labour force that is unemployed, from the number unemployed and the total labour force.Real Rate of ReturnThe inflation-adjusted return on an investment, using the Fisher equation rather than a simple subtraction.Income Elasticity of Demand CalculatorHow much quantity demanded responds to a change in income, from an old and new income and quantity.Bond yield to maturity (YTM)The return a bond earns if held to maturity, found by solving price for yield.Bond duration & convexityHow sensitive a bond’s price is to a change in yield, to first and second order.Yield to call (YTC)Approximate return on a callable bond if the issuer redeems it early.Cap rate (capitalisation rate)The unlevered return a rental property generates from its net operating income.Gross rent multiplier (GRM)A quick screen of property price against the rent it collects, before expenses.DSCR (debt service coverage ratio)Whether a property or business generates enough income to cover its debt payments.Asset turnover ratiosHow hard a company’s inventory, receivables and total assets are working to generate revenue.Free cash flow & yieldCash a business generates after the capital spending needed to keep running.Rent or buy comparisonNet cost of renting versus buying a home over the years you plan to stay.Car lease payment (money factor)Monthly lease payment from depreciation and finance charges.Real interest rate (Fisher equation)What an interest rate is worth once expected inflation is stripped out.PVGO (present value of growth opportunities)How much of a stock’s price reflects expected future growth, versus current earnings alone.Growing annuity present valuePresent value of a stream of payments that increases by a fixed rate each period.Degree of operating leverage (DOL)How much operating profit swings for a given swing in sales, given a company’s fixed cost base.Revenue valuation multiples (EV/Sales & P/S)Prices a company against its revenue, useful when earnings are thin or negative.Debt-to-capital ratioWhat share of a company’s permanent funding comes from debt rather than equity.Interest-only mortgageThe interest-only payment, and what it jumps to once principal repayments begin.Biweekly mortgage paymentTime and interest saved by paying half the monthly payment every two weeks instead.Price Elasticity of Supply CalculatorHow much quantity supplied responds to a price change, from an old and new price and quantity.Loss Ratio CalculatorInsurance loss ratio: claims paid as a percentage of premiums earned.EBIT CalculatorEarnings before interest and tax, from net income, interest and tax, with the resulting margin.Price per Square Metre CalculatorPurchase price divided by floor area in square metres, plus the price at a target rate per m².Basis Points CalculatorConverts basis points to a percentage or decimal, or a percentage back to basis points, both directions.P/E Ratio CalculatorPrice-to-earnings ratio from a share price and earnings per share, with the equivalent earnings yield.Earnings per Share CalculatorNet income per outstanding share, the building block behind the P/E ratio and other stock metrics.Interest Coverage Ratio CalculatorHow many times over a business can pay its interest bill from operating earnings (EBIT).Average Share PriceWeighted average price you paid across several share purchases at different prices and quantities.PV of AnnuityPresent value of a series of equal, regular payments, from the payment amount, interest rate and number of periods.Margin of Safety CalculatorHow far actual or budgeted sales can fall before a business hits its break-even point, in dollars and as a percentage.Dividend Per Share CalculatorDividend per share (DPS) from total dividends paid, preferred dividends and shares outstanding Market CapMarket capitalisation of a company from its share price and total shares outstanding.GDP DeflatorCalculates the GDP deflator from nominal and real GDP, the broadest measure of economy-wide price change.Inventory Turnover CalculatorInventory turnover ratio and days-to-sell from cost of goods sold and average inventory value.Effective Interest Rate CalculatorEffective annual rate from a nominal rate and compounding frequency, or the nominal rate needed for a target effective rate.Credit utilization ratioHow much of your available credit is in use, per card and overall.Bond equivalent yieldConverts a discount instrument price into an annualised coupon-style yield.Taxable equivalent yieldThe taxable yield needed to match a tax-free bond after tax.Insurance combined ratioWhether premiums collected cover claims and the cost of writing policies.Balance transfer savingsWhether moving a balance to a promo-rate card actually saves money.Blended interest rateThe single weighted rate that several loans are effectively costing.Sortino ratioRisk-adjusted return that only penalises downside volatility.Maximum drawdownThe worst peak-to-trough decline across a series of portfolio values.Modified internal rate of return (MIRR)A more realistic IRR that uses separate finance and reinvestment rates.Debt snowball vs avalancheCompares paying off smallest balances first against paying off highest rates first.Net effective rentThe real average rent after free months, allowances and operating costs.Days cash on handHow many days a business could cover its operating costs from cash reserves.Weighted average shares outstandingTime-weighted share count used as the denominator for EPS.Buyback impact on EPSHow a share repurchase changes earnings per share, all else equal.Annuity due vs ordinary annuityHow payment timing (start vs end of period) changes an annuity’s value.Economic value added (EVA)Profit left over after paying for the capital used to generate it.Reverse CAGR CalculatorGiven a CAGR rate, solve for the ending value, beginning value or number of years, whichever you do not already know.FIFO Inventory CalculatorCost of goods sold and remaining inventory value under first-in-first-out costing.US Powerball Payout CalculatorEstimated lump-sum and annuity payout from a Powerball jackpot, after your own cash-value and tax-rate assumptions.Cross Price Elasticity CalculatorHow demand for one good responds to a price change in a different good, and whether they are substitutes or complements.Average Variable CostVariable cost per unit produced, from total variable cost and quantity.Margin Loan CalculatorCurrent loan-to-value ratio, how far a portfolio can fall before a margin call, and interest cost.28/36 Rule CalculatorMaximum recommended housing payment and total debt payment under the 28/36 mortgage affordability rule.Commercial Rent Calculator AustraliaAnnual and monthly rent from a floor area and a rate per square metre, the standard way Australian commercial leases are quoted.Prorated SalaryWhat to pay for a partial pay period, from the full annual salary and the days actually worked.Payday Loan CalculatorTrue cost of a payday loan, including the total repayment and the equivalent effective annual interest rate (APR).PVIFA (Present Value Interest Factor of Annuity)The PVIFA factor for a given rate and number of periods, plus the present value of a chosen payment.Weekly Payments CalculatorConverts a loan or bill payment amount between weekly, fortnightly, monthly, quarterly and annual frequencies.Unlevered Beta CalculatorStrips a company's financial leverage out of its observed beta, to compare risk across companies with different debt levels.Altman Z-ScoreBankruptcy-risk score for a company from five balance-sheet and income ratios.Black-Scholes option priceTheoretical price of a European call and put option.Treynor ratioReturn earned above the risk-free rate, per unit of market (beta) risk taken.EV/EBITDA multiplePrices a company against its cash operating profit, independent of capital structure.Mortgage refinance breakevenHow many months of lower payments it takes to recoup the cost of refinancing.Deferred annuity present valueWhat a stream of future payments is worth today if it does not start for several years.Futures fair value (cost of carry)Theoretical futures price implied by the spot price, financing rate and yield.Mortgage points breakevenWhether paying upfront points for a lower rate pays off before you sell or refinance.Midpoint Method Elasticity of DemandPrice elasticity of demand using the midpoint formula, which gives the same result regardless of price direction.Return on Assets CalculatorReturn on assets (ROA) from net income and total assets, the profit generated per dollar of assets held.Labour Force Participation RateShare of the working-age population that is in the labour force, employed or actively looking for work.Annual Turnover CalculatorTotal annual revenue from monthly or quarterly sales figures, the everyday business meaning of turnover.Economic Profit CalculatorProfit after subtracting both explicit costs and the opportunity cost of resources used, not just accounting costs.Continuous Compounding CalculatorFuture value using continuous compounding, A = P times e to the rt, compared against ordinary compound interest.Portfolio Beta CalculatorThe weighted-average beta of a portfolio, from each holding’s individual beta and its share of the portfolio.Profit Loss CalculatorProfit or loss and profit margin from revenue and costs.Cost Price CalculatorWorks backward from a selling price and a margin or markup percentage to find the original cost price.Occupancy Rate CalculatorOccupancy rate for a rental property, hotel or facility, from occupied units and total available units over a period.Additional funds needed (AFN)External financing a growing business needs beyond what retained earnings cover.Accrual ratioEarnings-quality check comparing the change in net operating assets to their average.Cash flow coverage ratiosWhether operating cash flow covers current liabilities and total debt.High-low methodSplits a mixed cost into fixed and variable parts from its highest and lowest activity levels.Economic Order Quantity (EOQ)Order size that minimises combined ordering and holding costs for inventory.Herfindahl-Hirschman Index (HHI)Market concentration measured from the sum of squared market shares of each firm.Cobb-Douglas Production FunctionTotal output from labour and capital inputs given their productivity and output elasticities.Covered Interest Rate ParityNo-arbitrage forward exchange rate implied by the interest rate gap between two currencies.Put-call parityChecks or solves the no-arbitrage relationship between a call, a put and the underlying.Optimal hedge ratioShare of a spot position to cover with futures to minimise portfolio variance.Implied forward rateThe interest rate implied for a future period by two spot rates of different maturities.Credit spread (bond)The extra yield a corporate bond pays over a government bond of the same maturity.Jensen's alphaRisk-adjusted return a portfolio earned above what CAPM predicted.Information ratioExcess return over a benchmark per unit of tracking-error risk taken.Profitability indexValue created per dollar invested, for ranking or screening projects.Sinking fund paymentThe regular deposit needed to reach a target sum by a future date.Holding period returnTotal return from an investment, combining price change and income received.Actual cash value (ACV)What an insurer would pay for an item today, after wear and depreciation.ADR & RevPAR (hotel revenue)Average daily rate and revenue per available room for a lodging property.Bank reconciliationReconciles your cash book balance against the bank statement balance.Customer acquisition cost (CAC)What it costs, on average, to win one new customer, and how fast that cost is repaid.Customer churn & retention rateShare of customers lost over a period, and the flip side: how many you kept.GMROI (gross margin return on investment)How many dollars of gross profit each dollar tied up in inventory returns.Direct material price varianceWhether materials cost more or less than the standard (budgeted) rate.ARM (adjustable-rate) mortgagePayment during the fixed period, and the worst-case payment once the rate can adjust.Bond current yieldThe income return a bond offers at its present market price, ignoring capital gain or loss.Return on capital employed (ROCE)Operating profit generated per dollar of capital tied up in the business.Operating marginWhat share of revenue is left as operating profit, after cost of sales and running costs.SaaS customer lifetime value (LTV)What an average subscriber is worth over their time, weighed against acquisition cost.Margin CalculatorGross margin percentage from unit cost and selling price, with markup and profit shown alongside.Net Profit MarginNet profit margin from revenue and net income, the share of revenue left after every expense.

Growth

Growth rates for revenue, users and any other metric that moves period to period: YoY, MoM, QoQ and beyond, each with its own dedicated page.

All →

Year-over-year (YoY) growthGrowth between this period and the same period a year ago.Month-over-month (MoM) growthGrowth between this month and last month, with the annualised equivalent.Quarter-over-quarter (QoQ) growthGrowth between this quarter and the previous quarter, with the annualised equivalent.Week-over-week (WoW) growthGrowth between this week and last week, with the annualised equivalent.Day-over-day (DoD) growthGrowth between today and yesterday, with the annualised equivalent.Period-over-period (PoP) growthGrowth between any two comparable periods you define, with a custom annualising cadence.Compound monthly growth rate (CMGR)The smooth monthly rate that links a start and end value over several months.Annualised run rateExtrapolates a single period of revenue to a full-year figure.Rule of 40Checks whether growth rate plus profit margin clears the 40% SaaS health benchmark.User & customer growth rateNet growth rate for a user base once new signups and churned users are both counted.Revenue growth & target plannerGrowth achieved between two periods, and the revenue needed next period to hit a target rate.

Marketing

The core paid-media metrics: CPM, CPC, CPA, CTR, ROAS and more, each with the formula shown and worked examples.

All →

CPM (Cost Per Mille)Cost per 1,000 ad impressions, and the impressions or budget that go with it.CPC (Cost Per Click)Average cost per click from total spend and clicks, the core paid-search and paid-social metric.CTR (Click-Through Rate)Share of impressions that turned into a click, the standard measure of ad relevance.CPA (Cost Per Acquisition)Average spend needed to win one paying customer or completed sale.Conversion RateShare of visitors or clicks that completed the goal action, such as a purchase or sign-up.ROAS (Return On Ad Spend)Revenue earned for every dollar of ad spend, and the equivalent ROI percentage.CPL (Cost Per Lead)Average spend needed to generate one lead, before that lead becomes a paying customer.CPV (Cost Per View)Average cost per video view, the key metric for video and YouTube ad campaigns.CPI (Cost Per Install)Average spend needed to acquire one app install, the core mobile user-acquisition metric.Reach & FrequencyUnique people reached and average number of times each saw the ad, from total impressions.Break-Even ROASThe minimum ROAS an ad campaign needs to hit, from your profit margin, and the matching target CPA.

SEO

Keyword density, meta-tag length, backlink ratios and the other measurable parts of on-page and technical SEO.

All →

Keyword DensityHow much of a page's word count is made up of one target keyword or phrase.Title Tag Length CheckerCharacter and approximate pixel width of a page title against Google's search-result guideline.Meta Description Length CheckerCharacter count of a meta description against the guideline before search results truncate it.Dofollow vs Nofollow Backlink RatioThe split between dofollow and nofollow backlinks, as a ratio and as a share of the total.Core Web Vitals CheckerRates LCP, INP and CLS against Google's published Good, Needs Improvement and Poor thresholds.Text-to-HTML RatioThe share of a page's total weight that is visible text, versus markup, scripts and styling.Anchor Text DiversityThe share of inbound anchor text that is exact-match, partial-match or branded/generic.

Real Estate

Investment property maths: rule-of-thumb screens, loan-to-value, debt yield and flip-and-rental returns.

All →

Loan-to-Value (LTV)What share of a property's value is being borrowed, the core metric lenders use to size risk.Debt Yield RatioNet operating income as a share of the loan amount, a lender risk check on the loan size.Price per Square FootPurchase price divided by floor area, plus the implied price at a target rate per sq ft.1% Rule ScreenerChecks monthly rent as a percentage of price against the commonly cited 1% screening threshold.House Flip ROIProfit and return on cash invested for a fix-and-flip project, ARV to selling costs.BRRRR Cash-on-Cash ReturnCash left in a Buy, Rehab, Rent, Refinance, Repeat deal after refinancing, and its return.Vacancy RateVacant unit-days as a share of total available unit-days across a rental property or portfolio.

E-commerce

Order economics and inventory maths for online and retail sellers: AOV, LTV, reorder points and break-even.

All →

Average Order Value (AOV)Average revenue per order, from total revenue and number of orders.E-commerce Customer Lifetime ValueCustomer value from average order value, orders per year and years as a customer.Inventory Reorder PointStock level at which to reorder, from daily usage, lead time and safety stock.Safety Stock CalculatorBuffer stock needed to cover demand variability at a chosen service level.Shipping Cost Per UnitAverage shipping cost per unit, from total shipping spend and units shipped.E-commerce Break-Even UnitsUnits and revenue needed to cover fixed costs, from price and variable cost per unit.Cart Abandonment RateShare of carts created that did not end in a completed purchase.

Insurance

Coverage-sizing maths for life, umbrella and general insurance: how much cover, not what it costs.

All →

Life Insurance Needs (DIME Method)Rough coverage estimate from debts, income replacement, mortgage and education costs.Premium Per $1,000 of CoverageAnnual premium rate per $1,000 of coverage, for comparing quotes of different sizes.Deductible vs Premium Break-EvenYears of premium savings needed to offset paying a higher deductible once.Umbrella Policy Coverage GapGap between a target liability protection level and existing auto and home liability limits.Human Life Value MethodPresent value of future net income, an actuarial approach to sizing life insurance.

HR & Workforce

Staffing and workforce maths: full-time equivalents, turnover, overtime pay and leave accrual.

All →

FTE (Full-Time Equivalent)Full-time equivalent headcount from a mix of full-time and part-time staff hours.Employee Turnover RateTurnover rate from separations and average headcount over a period.Overtime PayTotal pay from regular and overtime hours at a chosen overtime multiplier.PTO Accrual RatePTO hours accrued per pay period and running balance after periods worked.Staffing RatioStaff-to-units ratio and its inverse, for any service where staff cover units served.