Property flip calculator
Buy, refurbish, sell. This shows the profit at the price you are thinking of offering, and the most you could offer and still make the profit you want.
How this is calculated
Total cost is the offer plus stamp duty on it, the refurbishment, legal, broker and survey fees, holding costs for the months you own the property, and the cost of money on the purchase price and refurbishment for the same period.
Profit is the sale price less the estate agent fee and the total cost. Return on cost divides the profit by the total cost, and the yearly figure scales it to twelve months so projects of different lengths can be compared.
The maximum offer is found by searching for the price at which the profit equals your target, because stamp duty changes with the price.
Tax on the profit is not included. A flip is usually taxed as trading income for an individual or as company profit, not as a capital gain, and the rate depends on your circumstances.
Rates and assumptions used
| SDLT up to £125,000 | 0% |
| £125,001 to £250,000 | 2% |
| £250,001 to £925,000 | 5% |
| Additional property surcharge | 5% of the whole price, from £40,000 |
| Tax on the profit | not included |
Statutory rates last checked July 2026. Source: HMRC and gov.uk.
Worked example
Offer £150,000 on a property that will sell for £215,000 once £25,000 of work is done. Stamp duty with the surcharge is £8,000. Add £5,000 of legal, broker and survey fees, £2,800 of holding costs over eight months and £10,500 for the cost of money, and the total cost is £201,300. After a £3,225 agent fee on the sale, the profit is £10,475 before tax. To make £20,000 instead, the offer would need to come down to about £141,600.
Common questions
What profit should I aim for?
Enough to absorb the things that go wrong: a lower sale price, a longer sale, or works that cost more than planned. Many investors set a minimum profit in pounds and a minimum return on cost, and walk away from deals that miss either.
Why include the cost of money if I use my own cash?
Because that cash could be earning something elsewhere, and a project that ties it up for a year should beat that. If you borrow, it is simply the interest.
Is a flip taxed as a capital gain?
Usually not. HMRC generally treats buying to sell at a profit as trading, so the profit is taxed as income, or as company profit if you buy through a company. Speak to an accountant before you start.
Maximum offer and BRRR calculator
Work back from the done-up value to the most you can pay and still get your money out.
Refurbishment budget calculator
Room by room works with materials, labour and contingency, using observed material prices.
Buy to let investment calculator
Cash flow, yield, return on cash, a rate stress test and a projection with IRR.