Everyday calculators

Unit conversion, home and trade quantities, food and the practical calculations daily life runs on.

Conversion

Unit converters that show the full ladder of equivalents at once, not just the one pair you asked for.

Length & distanceMetric and imperial length, from millimetres to nautical miles.Weight & massGrams, kilograms, pounds, ounces, stone and tonnes.Volume & capacityLitres, millilitres, gallons, pints, cups and cubic units.AreaSquare metres, hectares, acres and square feet.SpeedKilometres per hour, miles per hour, metres per second, knots.TimeSeconds through to centuries.Digital storageBytes, kilobytes, mebibytes and the binary versus decimal split.PressurePascals, bar, psi, atmospheres and millimetres of mercury.EnergyJoules, calories, kilowatt-hours and BTU.PowerWatts, kilowatts, horsepower and BTU per hour.AngleDegrees, radians, gradians and turns.Cooking measuresCups, spoons, millilitres and fluid ounces for the kitchen.TemperatureCelsius, Fahrenheit, Kelvin and Rankine.Fuel economyLitres per 100 km, miles per gallon and km per litre.Height & weight (imperial ↔ metric)Feet-and-inches and stone-and-pounds, both ways.TorqueNewton-metres, foot-pounds, inch-pounds and kilogram-force metres.Paper quantitySheets, quires and reams, the units the printing and stationery trade uses.Concentration (ppm, ppb, %)Parts per million, parts per billion and percentage, as the same ratio expressed differently.12-hour ↔ 24-hour (military) timeClock time converted to 24-hour military format, and back.

Home & build

Quantities and sizing for renovation, landscaping and trade work: paint, tiles, concrete, roofing and more.

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Paint requiredLitres of paint for walls, allowing for doors and windows.Flooring & tilesBoxes of tiles or boards needed, including wastage.Concrete volumeCubic metres for a slab, footing or set of posts.Mulch, soil & gravelBulk material for a garden bed at a given depth.Roof pitch & rafter lengthAngle, slope factor and true roof area.Fencing & decking materialsPosts, rails and boards for a run of fence or deck.Air conditioner sizingCooling capacity for a room, adjusted for sun and occupancy.Tank & pool volumeCapacity of a rectangular or round tank in litres.Drywall sheets neededPlasterboard sheets for a room, allowing for openings and waste.Bricks or blocks neededMasonry units for a wall, from unit size and mortar joint thickness.Stair rise & runStep count, riser height and comfort check for a straight staircase.Pavers & bedding sandNumber of pavers and bedding sand volume for a patio or path.Roof shingle bundlesBundles of shingles needed, accounting for slope and waste.Board feet of lumberBoard feet and cost for a batch of dimensional lumber.Baluster / spindle spacingEven spindle count and gap for a stair or deck railing.Wallpaper rolls neededRolls required for a room, accounting for pattern repeat.Wall stud countStuds needed for a wall on a chosen centre spacing, plus openings.Ladder angle & base distanceSafe base distance and length for a leaning ladder, using the 4-to-1 rule.Insulation thickness & coverageThickness needed to hit a target R-value, and rolls required for an area.

Everyday

Practical comparisons for shopping, travel, cooking and time: the small calculations that add up.

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Trip fuel costFuel and time for a journey, split between passengers.Unit price comparisonWhich pack is actually cheaper per unit.Recipe scalerRescales quantities and adjusts baking time.Aspect ratio & screen sizeResize while keeping proportions, or find screen dimensions.Pizza & round-item valueArea per dollar: the honest way to compare sizes.Reading & speaking timeHow long a word count takes to read aloud or silently.Password strengthEntropy in bits and how long a brute force would take.Coffee brew ratioGrounds and water for a chosen strength.Hours of work to buy somethingPrices a purchase in hours of your life.Battery charge timeHow long a device takes to charge from its current level to a target level.Typing speed (WPM)Gross and net words per minute, and accuracy, from a timed typing sample.Luggage linear inchesChecks a bag against an airline’s combined length + width + height limit.Cost of a meetingWhat a meeting actually costs in attendee salary time.True cost per mile to driveAll-in running cost of a vehicle, spread across the miles driven.Weight of a pile of cashHow much a dollar amount weighs in bills or coins.2-stroke fuel mix ratioOil to add to a volume of petrol for a chosen mix ratio.Generator sizingGenerator capacity needed to cover a set of appliances, including starting surge.LED bulb savingsElectricity and replacement-bulb savings from switching to LED lighting.Event tables & seatingTables needed for a guest count, for round or rectangular tables.Pomodoro session plannerHow many focused work intervals a task will take, breaks included.Money saved by quitting smokingWhat not buying cigarettes adds up to over time.Roll length remainingHow much material is left on a roll, from its diameter and material thickness.Cost of a showerWater and water-heating energy cost for one shower.EV home charging cost & timeCost and time to charge an electric vehicle from one charge level to another.Binge-watch time plannerTotal time to finish a TV series, and how many days that takes.Moon phase finderThe approximate Moon phase on any date, from the lunar synodic cycle.Weighted blanket sizeRecommended blanket weight from body weight, using the common 10% rule.Mobile data usageDaily and monthly data use from your mix of everyday activities, and how long a data cap will last.

Food

Kitchen and brewing ratios: baker’s percentages, dilutions, yields and the maths behind a recipe that scales.

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Baker’s percentage & hydrationExpresses every dough ingredient as a percentage of the flour weight, the way bakers formulate recipes.Brine strengthSalt needed to make a brine of a given strength, by weight of the water.ABV from gravity readingsAlcohol by volume of a home-brewed beer or wine from hydrometer readings.Alcohol dilutionWater needed to cut a spirit down from one ABV to a weaker target ABV.Yeast type converterA quantity of yeast converted between active dry, instant and fresh (cake) forms.Self-rising flour from all-purposeBaking powder and salt to turn plain flour into self-rising flour.Rice to water ratioWater needed to cook a given amount of rice, and the approximate cooked yield, by rice type.Dry to cooked pasta weightHow much a portion of dry pasta weighs once boiled, given its typical expansion factor.Party drink plannerTotal drinks needed for a party, split across beer, wine and spirits.Cake servingsHow many servings a round or rectangular cake yields at a given slice size.Ice cream overrunHow much the volume of a churned ice cream mix has grown from the air whipped into it.

Pets

Sizing, feeding and age-conversion maths for the animals in your household, from crate size to daily calories.

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Dog age in human yearsA dog's age converted to a human-equivalent age using the epigenetic-clock formula.Cat age in human yearsA cat's age converted to an equivalent human age using the standard veterinary chart.Pet gestation & due dateExpected birth date range for a common pet or farm animal, from the breeding date.Dog & cat daily caloriesDaily energy needs from resting energy requirement and an activity factor.Dog daily water intakeRoughly how much water a dog needs per day, by activity level.Dog crate sizeMinimum crate dimensions so a dog can stand, turn around and lie stretched out.Turtle tank sizeMinimum water volume for a pet turtle based on shell length.Chicken coop & run sizeMinimum floor space for a flock, depending on how much outdoor access they get.Dog chocolate toxicity riskTheobromine dose from chocolate eaten, checked against published toxicity thresholds.Rabbit cage sizeMinimum enclosure dimensions based on a measured hop, body length and standing height.Dog daily food amountDaily feeding amount as a percentage of body weight, by life stage.Cost of owning a petFirst-year and ongoing costs from your own monthly and one-off figures.