Thinking of buying a property, doing it up, and selling it on for a profit? Smart move. But the numbers have to stack up before you do anything else. Our buy to sell mortgage calculator gives you a fast, honest picture of what your project could cost to finance, and what you might realistically pocket once the work’s done and the sale completes.
Pop in your figures below. Adjust them. See where the profit lands. No sign-up, no sales pitch, just the answer you came for.
Estimate your finance costs, profit and return on a buy-to-sell (flip) project in seconds.
For illustration only. Figures are estimates based on the inputs above and do not constitute a quote or financial advice. SDLT uses England & Northern Ireland residential rates (April 2025). Your circumstances, lender terms and final costs may differ. Clever Lending is authorised and regulated by the FCA.
Short answer: not in the way most people picture it.
A standard residential mortgage is built for someone buying a home to live in for years. Lenders don’t like the idea of you selling within a few months, and most won’t touch a property that needs serious work before it’s even habitable. So if you’re buying to sell, a normal mortgage usually isn’t the tool for the job.
What actually funds these projects is short-term property finance. Most often that’s a bridging loan, or where there’s a refurbishment involved, refurbishment or light development finance. People still call it a “buy to sell mortgage” because that’s how the goal feels: borrow against the property, get the project done, sell, repay. The calculator above is built around exactly that.
If that sounds like jargon, don’t worry. The whole point of talking to a specialist is that you don’t have to be one.
It takes about a minute. Here’s what each field means and where the numbers come from.
Purchase price
What you're paying for the property.
Loan to value (LTV)
How much of the purchase price you want to borrow. Short-term lenders typically go up to around 70 to 75%, so your deposit covers the rest.
Refurbishment / works cost
Your honest budget for the renovation. Be realistic, because this is where flips go wrong.
Expected resale value (GDV)
What you reckon you'll sell for once it's finished. Lenders call this the Gross Development Value.
Loan term
How many months you'll hold the property, from purchase to sale. Build in a buffer.
Monthly interest rate
short-term finance is usually priced per month, not per year.
Open Advanced costs and you can layer in the arrangement fee, stamp duty, legal fees, your broker fee and the selling costs, the bits that quietly eat into profit if you forget them. The results show your gross loan, the deposit you’ll need, total interest, your all-in cash invested, and the two numbers that really matter: estimated net profit and return on the cash you put in.
Say you spot a tired three-bed at £200,000. You borrow 75% (£150,000), so you’re putting in a £50,000 deposit. You budget £30,000 for the refurb and expect to sell at £290,000 after a nine-month project.
Run that at a 0.89% monthly rate, with a 2% arrangement fee and the additional-property stamp duty applied, and you’re looking at roughly £12,000 in interest, around £11,500 in stamp duty, plus legal and selling costs. After everything, the estimated profit lands near £26,000, a return of close to 28% on the cash you actually invested.
Change one number (a softer sale price, a refurb that overruns, an extra three months holding the loan) and watch how quickly that profit moves. That’s the real value of running it before you offer, not after.
Profit on paper and profit in the bank are two different things. The gap is usually made up of:
Buy a property that isn't your main home and you'll almost always pay the higher rate, including the additional-property surcharge. On a £200,000 purchase that's thousands. Check current rates on GOV.UK before you commit.
The arrangement fee (often 1 to 2% of the loan) plus the monthly interest, which adds up the longer you hold.
On the way in, and again on the way out.
Estate agent commission and conveyancing when you sell.
Every experienced flipper keeps a buffer. Surveys, slipped completions, a boiler that wasn't in the plan.
Short-term lenders care about three things more than anything else: the property, the exit, and you.
The property needs to be worth what you say it is, so they’ll want a valuation. The exit is how you’ll repay the loan; for a flip, that’s the sale, so they’ll want to believe your resale figure is achievable. And you matter too: lenders are reassured by previous projects, a sensible plan, and a realistic budget. You don’t need a long track record to get started, but a well-thought-through deal always gets a warmer reception.
This is where a broker earns their keep. We know which lenders like which deals, what they’ll accept, and how to present your project so it’s taken seriously. That’s the difference between a “yes” and a “we’ll pass.”
It can be a genuinely good way to make money from property, but it isn’t passive, and it isn’t risk-free.
It tends to work when:
You’ve found the right property at the right price, your refurb budget is honest, and the local market supports your resale figure. Speed and a tight cost grip are everything.
The market softens between buying and selling, the works overrun, or you’ve underestimated the holding costs. The calculator is there precisely so you can stress-test those scenarios before your money’s on the line.
If the numbers look tight, that’s useful to know now. If they look strong, let’s talk about funding it properly.
We’re a specialist property finance brokerage, authorised and regulated by the Financial Conduct Authority. We spend our days arranging exactly this kind of short-term, project-led lending: bridging, refurbishment and development finance. We know the market and the lenders inside out.
Straightforward, well-structured finance. The kind of clever thinking the name suggests.
Speak to a specialist today. Get a tailored quote or call us on 0800 316 2224. We respond within 24 working hours.
Not usually a standard residential mortgage. Those are designed for long-term owner-occupiers, and most lenders won't lend on a property that needs major work or will be sold within months. Buy-to-sell projects are normally funded with bridging or refurbishment finance instead, which is what this calculator is built around.
Expect to put in around 25 to 30% of the purchase price, since short-term lenders typically lend up to 70 to 75%. You'll also need to fund the refurbishment and the buying costs, so plan your cash flow for the whole project, not just the deposit.
In practice, often yes. “Buy to sell mortgage” describes the goal; a bridging loan (or refurbishment finance) is usually the product that delivers it. Both are short-term and designed to be repaid when you sell or refinance.
It's normally charged monthly rather than annually, because you only hold the loan for a short time. Interest is often “rolled up”, meaning it's added to the loan and paid off in one go when you sell, so you're not making monthly payments while the project's underway.
Yes, in almost all cases, and usually at the higher rate that applies to additional properties. It's one of the biggest costs to factor in, so include it in the Advanced section of the calculator. Always check current rates on GOV.UK.
Typically anywhere from a few months up to around 18 to 24 months, depending on the lender and the scale of the work. Build a sensible buffer into your term, because sales can take longer than expected.
Often, yes. Short-term lenders focus heavily on the property and your exit plan. First-time projects and adverse credit can both be workable with the right lender. This is exactly where having a specialist broker helps.
Short-term finance is built for speed and can sometimes complete in a couple of weeks, though timescales depend on the property, the valuation and your solicitors. Get in touch early and we'll give you a realistic timeline.
No. It's an illustration to help you plan. Your actual costs depend on the lender, the property and your circumstances. For real figures, speak to our team.
Email us directly with your enquiry by clicking here or using our email [email protected].
