What this calculator does
Transfer duty is charged on a sliding scale, and the thing people get wrong is assuming the top rate applies to the whole price. It does not. Each rate applies only to the part of the price inside its own band, exactly like income tax, which is why the effective rate is always well below the marginal one.
On the example scale here a $750,000 purchase attracts $18,250 of duty. The marginal rate at that price is 4.5 per cent, but the effective rate across the whole price is 2.43 per cent, and mistaking one for the other overstates the bill by nearly $16,000.
The formula
The scale is entered as threshold and rate pairs. For each band, the amount of the price falling inside it is the lesser of the price and the next threshold, minus this threshold. That amount is multiplied by the band's rate and the results are added. No scale is built in, because duty rates differ by jurisdiction and change with most budgets, and a figure baked into this page would be wrong within a year.
| Term | Meaning |
|---|---|
| Threshold | The price at which a band starts. The first is usually zero. |
| Marginal rate | The rate applying to the next dollar of price. What people usually quote. |
| Effective rate | Total duty divided by the whole price. Always lower than the marginal rate on a progressive scale. |
| Concession | A reduction applied after the calculation, such as a first-home or off-the-plan rebate. |
The inputs explained
| Field | What to enter |
|---|---|
| Property price ($) | The dutiable value, which is usually the purchase price but may be the market value if that is higher. |
| Scale as threshold:rate pairs | The scale, as threshold:rate pairs separated by commas. Entering 0:1.25, 200000:1.5 means 1.25% applies from zero and 1.5% from $200,000. Get the current scale from your own revenue office. |
| Fixed amount added ($) | A flat amount some scales add on top of the percentage component. |
| Concession or rebate ($) | Any concession or rebate, subtracted at the end. The result is floored at zero. |
When to use it
Budgeting for a purchase
Duty is usually the largest single transaction cost and it is payable in cash rather than borrowable, so it belongs in the deposit calculation rather than the loan. Work it out before setting a price limit, not after.
Comparing two jurisdictions
Enter each scale in turn at the same price. The difference between states or countries at the same purchase price is often tens of thousands, and it is the kind of thing that changes where a purchase makes sense.
Checking the cost of stretching your budget
The duty on the next $10,000 output shows the marginal cost of bidding higher. Near a threshold, going a dollar over can cost considerably more than a dollar.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How does duty rise with the price?
The same scale applied at different purchase prices.
| Purchase price | Duty payable | Effective rate on the whole price | Marginal rate at this price |
|---|---|---|---|
| $300k | $4,000.00 | 1.33% | 1.50% |
| $500k | $7,000.00 | 1.40% | 1.50% |
| $750k | $18,250.00 | 2.43% | 4.50% |
| $1000k | $29,500.00 | 2.95% | 4.50% |
| $1500k | $57,000.00 | 3.80% | 5.50% |
| $2000k | $84,500.00 | 4.23% | 5.50% |
How much does the scale itself matter?
The price is the same in every row. Only the scale changes.
| Scale | Duty payable | Effective rate on the whole price |
|---|---|---|
| 0:0, 600000:5 | $7,500.00 | 1.00% |
| 0:1.25, 200000:1.5, 5000… | $18,250.00 | 2.43% |
| 0:2, 500000:6 | $25,000.00 | 3.33% |
| 0:4 | $30,000.00 | 4.00% |
| 0:5.5 | $41,250.00 | 5.50% |
Questions
Why is no scale built in?
Because duty rates differ by jurisdiction and change with most budgets. A rate hard-coded here would be wrong within a year and there would be no way for a reader to tell. Get the current scale from your revenue office and enter it.
How do I enter the scale?
As threshold:rate pairs separated by commas, lowest first. 0:1.25, 200000:1.5 means 1.25 per cent applies from zero up to $200,000 and 1.5 per cent above that. The calculator sorts them if you enter them out of order.
Does the top rate apply to the whole price?
No, and this is the most common misunderstanding. Each rate applies only to the portion of the price inside its band, so the effective rate is always lower than the marginal rate. The band table shows exactly where each part of the price landed.
What about foreign buyer surcharges or first home concessions?
A surcharge can be approximated by raising the rates or adding a fixed amount. A concession goes in the concession field, which is subtracted at the end. Anything more complex than that needs the actual rules.
Is duty payable on the price or the valuation?
Generally on the higher of the two, which matters for transfers between related parties. Enter whichever applies to you as the dutiable value.
Duty is a cash cost at settlement, so it belongs alongside loan-to-value when working out a deposit. For what happens after you own it, see property holding cost and break-even sale price.