Property Flip Profit Calculator UK
Work out the net profit, return on investment and profit on GDV for a buy-refurbish-sell project. Stamp duty is not an estimate: it is calculated from the real rate tables for England & NI, Scotland and Wales at investor rates.
Your numbers
% of sale price. Use the figure in your agent's quote.
Both sets of legals, sourcing and other one-off costs.
Finance & holding costs
Purchase to completing the sale.
Council tax, insurance, utilities.
Your results
- Net profit
- £18,572
- Return on project cost
- 9.9%
- Return on cash
- 20.6%
- Profit on GDV
- 8.8%
after purchase tax, selling, finance and holding costs
profit ÷ total project cost
profit ÷ cash needed
profit ÷ sale price
- SDLT (England & N. Ireland)additional-property rates
- £7,300
- Finance costs£98,000 bridge: interest and fees over 6 months
- £5,978
- Holding costs£250 a month for 6 months
- £1,500
- Total project costpurchase + refurb + tax + costs + finance + holding
- £188,278
- Cash neededtotal project cost less the loan
- £90,278
- Selling costsagent fee at 1.5%
- £3,150
Interest is simple monthly interest on the full loan for the project length, which is what retained or serviced bridging charges. Rolled-up interest that compounds monthly costs slightly more.
Free to use, no sign-up needed. Figures are estimates for guidance, not financial or tax advice.
How the flip profit calculator works
A flip is the simplest strategy to describe and the easiest to get wrong: buy, refurbish, sell, keep the difference. The difference only exists if every cost is counted. This calculator uses the same engine as Dealist's deal analyser and treats stamp duty as a first-class cost rather than an afterthought.
Total project cost
Total project cost = purchase price + refurbishment + stamp duty + legal and other costs + finance and holding costs. The stamp duty figure comes from the real 2026 tables at additional-property rates, because a flipper who already owns a home pays the surcharge: SDLT plus 5% per band in England and Northern Ireland, LBTT plus the flat 8% ADS in Scotland, or the LTT higher-rates table in Wales. Change the jurisdiction and the whole calculation follows.
Finance and holding costs
Every month you own the property costs money. Bridging interest = loan × monthly rate × months, charged on the full loan for the whole project, which is how retained and serviced bridging work (rolled-up interest that compounds costs slightly more). A mortgage's annual rate is charged as a twelfth each month. Arrangement and exit fees are a percentage of the loan. Holding costs = monthly council tax, insurance and utilities × months. The defaults are a six-month project on a 70% bridge at 0.85% a month with a 1% arrangement fee and £250 a month of holding costs; change any of them, or choose cash.
Selling costs
Selling costs = sale price × estate agent fee. The default is 1.5%; use the fee in your agent's quote and check whether it is quoted plus VAT. Add your selling legals into the other-costs field if you have not already.
Net profit
Net profit = sale price − total project cost − selling costs. This is cash profit before tax. Because flipping is normally a trading activity, the tax treatment differs from a rental sale, which is one of the questions worth an hour of an accountant's time before you start.
The three return measures
Return on project cost = net profit ÷ total project cost × 100 measures the profit against everything the project cost, including the part a lender funds. Return on cash = net profit ÷ cash needed × 100 tells you how hard your own money worked, where cash needed is the total project cost less the loan. Profit on GDV = net profit ÷ sale price × 100 is the developer's risk measure: how much margin sits between you and a disappointing sale. A deal can show a healthy return yet a thin profit on GDV, so look at all three before committing.
Worked example
You buy a dated semi for £140,000 with a 70% bridging loan at 0.85% a month, spend £30,000 on a full cosmetic refurbishment with a new kitchen and bathroom, and 6 months after buying sell for £210,000 through an agent charging 1.5%. Council tax, insurance and utilities cost £250 a month while you own it.
| Purchase price | £140,000 |
| Refurbishment | £30,000 |
| SDLT (additional-property rates) | £7,300 |
| Legal and other costs | £3,500 |
| Bridging interest (£98,000 at 0.85% a month for 6 months) | £4,998 |
| Arrangement fee (1% of the loan) | £980 |
| Holding costs (£250 a month for 6 months) | £1,500 |
| Total project cost | £188,278 |
| Cash needed (after the £98,000 bridging loan) | £90,278 |
| Sale price | £210,000 |
| Estate agent fee (1.5%) | £3,150 |
| Net profit | £18,572 |
That is a return of 9.9% on the total project cost of £188,278 and a profit on GDV of 8.8%, before tax. The bridging loan funds £98,000 of that cost, so the cash you need is £90,278: measured on that, the profit is a return of 20.6% on the £90,278 you put in. Notice the £7,300 of stamp duty and the £7,478 of finance and holding costs: leave them out of your appraisal and the project looks £14,778 more profitable than it really is. Figures are rounded to the nearest pound.
Frequently asked questions
How do I calculate profit on a property flip?
Net profit = sale price minus everything the project cost you: the purchase price, refurbishment, stamp duty, legal fees on both the purchase and the sale, finance and holding costs, and the estate agent fee when you sell. Forgotten costs are an easy way for a flip to fail, so list every line before you offer.
What is profit on GDV and what percentage is good?
Profit on GDV is net profit divided by the gross development value (your sale price). There is no official benchmark: set your target by the risk you are taking. The thinner the margin, the less it takes (a modest overrun in works, a soft sale price) to erase the profit, so test the deal at a lower sale price and a higher works cost before you commit.
Do I pay the additional stamp duty surcharge when flipping?
Yes, if you already own a home. The purchase of a flip is then an additional dwelling, so the surcharged rates apply: 5% extra on each SDLT band in England and Northern Ireland, the flat 8% ADS in Scotland, or the LTT higher-rates table in Wales. The surcharge is not refundable when you sell the flip, because you are not replacing your main residence.
What tax do I pay on flip profits?
Flipping is usually treated as trading, so profits are typically subject to income tax and Class 4 National Insurance if you trade as an individual (for 2026 to 2027, Class 4 is 6% on profits over £12,570 up to £50,270 and 2% above that), or corporation tax in a limited company, rather than capital gains tax. The right structure depends on scale and your wider position. This calculator shows pre-tax profit; take advice from an accountant before your first project.
Which costs are easy to forget?
Finance costs on bridging (monthly interest plus arrangement and exit fees), council tax and utilities while you hold it, insurance for an empty property under refurbishment, two sets of legal fees, and selling costs. The calculator has its own fields for the project length, bridging or mortgage finance and monthly holding costs, so they come off your profit instead of being forgotten.
What is the 70% rule and does it apply in the UK?
The 70% rule is an American heuristic: pay no more than 70% of the after-repair value minus refurbishment costs. A simple alternative is to work backwards from a target profit on GDV: decide the profit you need, deduct it and all costs from the realistic end value, and what remains is your maximum offer.
How long should I plan for a flip?
Plan the whole timeline end to end: completing the purchase, the works, then marketing the property and completing the sale, each of which can take months. Every extra month adds holding and finance costs, which is why the timeline belongs in your numbers, not just your hopes.
Sources
The stamp duty in this calculator uses the rates each tax authority publishes, applied to the nation you choose. Everything else, such as rent, mortgage rate and costs, is an assumption you set. The other rules this page describes come from the official pages listed under Other rules on this page. Last reviewed . Rates can change at a Budget, so confirm the current figure with the tax authority or your conveyancer before you commit to a purchase.
England and Northern Ireland (Stamp Duty Land Tax)
- Stamp Duty Land Tax: residential property rates (opens in a new tab) · HMRC, GOV.UK
- Higher rates of Stamp Duty Land Tax (opens in a new tab) · HMRC, GOV.UK
- Rates of Stamp Duty Land Tax for non-UK residents (opens in a new tab) · HMRC, GOV.UK
- Stamp Duty Land Tax: corporate bodies (opens in a new tab) · HMRC, GOV.UK
Scotland (Land and Buildings Transaction Tax)
- LBTT residential property rates and bands (opens in a new tab) · Revenue Scotland
- The Additional Dwelling Supplement (ADS) (opens in a new tab) · Revenue Scotland
Wales (Land Transaction Tax)
- Land Transaction Tax rates and bands (opens in a new tab) · Welsh Revenue Authority, GOV.WALES
- Higher rates of Land Transaction Tax: overview (opens in a new tab) · Welsh Revenue Authority, GOV.WALES
Other rules on this page
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