UK Rent vs Buy Calculator
A proper UK rent versus buy comparison. It puts stamp duty, mortgage interest, ongoing maintenance and selling costs on the buying side, and the opportunity cost of the deposit on the renting side, then tells you which one leaves you better off over your chosen horizon.
Explain like I'm 5 (what even is this calculator?)
Imagine two versions of you. One buys a house with a deposit and a mortgage. The other rents and invests the same deposit in a stocks and shares ISA. Every year, both of them pay their housing bill: the buyer pays the mortgage plus repairs and insurance, the renter pays rent. At the end of ten, fifteen or twenty years, we work out what each of them has left. The one with more money wins. This tool runs that race for you.
Calculate
At a glance
- Net cost of buying—
- Net cost of renting—
- Difference—
- Break-even year—
Buying side detail
- Stamp Duty (SDLT)—
- Other upfront costs—
- Monthly mortgage payment—
- Total mortgage paid over horizon—
- Total maintenance—
- Final house value—
- Remaining loan balance—
Renting side detail
- Total rent paid—
- Total insurance paid—
- Final investment portfolio—
Year by year
| Year | Cumulative net cost: buying | Cumulative net cost: renting | House value | Portfolio |
|---|
Show workings
Mortgage monthly uses the standard annuity formula M = P r (1+r)^n / ((1+r)^n − 1). Remaining balance uses the amortisation identity. Maintenance is charged on the house value at the start of each year. The investment pot starts at deposit + upfront costs and compounds yearly at the chosen return. SDLT uses the 2025/26 England and Northern Ireland bands; Scotland uses LBTT and Wales uses LTT, neither of which this tool covers.
The real question: it's not rent versus mortgage, it's outcomes over time
"Renting is throwing money away" is one of those statements that sounds obviously true, which is usually a bad sign. The reverse, "buying is always a good investment", is no better. The honest answer is that buying can win or lose against renting depending on three things: how long you stay put, what the alternative investment would have returned, and what the local housing market does while you own. Change any of those and the verdict can flip.
A proper comparison puts every pound from each side on the scoreboard. On the buying side that means the deposit, stamp duty, solicitor, survey, mortgage fees, every monthly payment, maintenance, and the costs of selling when you eventually leave. On the renting side it means every month's rent and insurance, but also the investment gain on the cash that would otherwise have been locked into bricks and mortar. Leave any of those out and you are lying to yourself.
How the calculator works
For buying, it adds up the cash you put in (deposit, upfront costs, mortgage payments, maintenance) and subtracts the cash you get back at the end (final house value minus remaining loan minus selling costs). That gives you the net cost of buying over your horizon.
For renting, it adds up the rent and insurance, then subtracts the investment gain on the cash that would have been the deposit plus upfront costs. If you leave the "invest the difference" option on, any month where buying would have cost more than renting, the saving gets added to the investment pot too. That gives you the net cost of renting over the same horizon.
Whichever number is lower, wins. The year-by-year table shows you when buying overtakes renting, which is the break-even point most people actually want to see.
Hidden costs of buying that most people forget
Stamp duty is the obvious one. On a £300,000 standard purchase you are looking at £5,000 straight to HMRC; on £500,000 it is £12,500. First-time buyer relief softens it up to a £500,000 purchase, but above that threshold you pay standard rates with no relief at all. Then there is the solicitor (usually £1,200 to £2,000), a homebuyer survey (£400 to £1,000), mortgage arrangement fees (typically £999 to £1,999), and valuation fees. Add them up and you can easily spend £6,000 to £10,000 before the keys are in your hand.
Ongoing costs get underestimated even more often. Boilers die. Roofs leak. Windows rot. A sensible budget is roughly 1% of the property value per year averaged over a decade, which on a £300,000 home is £3,000 a year, or £30,000 across ten years. Leasehold flats add ground rent and service charge on top, sometimes running to several thousand pounds a year on their own.
And then you have to sell. Estate agent fees typically land at 1% to 1.8% of the sale price, plus another £1,000 to £2,000 in legal fees. On a £400,000 sale that is easily £5,000 to £8,000 gone before the money hits your account.
Across a ten-year ownership, upfront, ongoing and exit costs often total 5% to 10% of the purchase price. That is the number most back-of-envelope "rent versus buy" chats quietly skip.
Hidden benefits of renting
Renting gets bashed because it feels like handing money to a landlord for nothing. But it buys you things too. Flexibility, for a start: you can move for a job, a relationship, or because the street has become noisy, without the 2% to 3% friction cost of selling a house. You are not on the hook when the boiler goes or the roof starts leaking; that is the landlord's problem. Your deposit can sit in a stocks and shares ISA earning compound returns, rather than being locked in an asset you can only turn into cash by moving out.
None of this means renting beats buying. It means the comparison is not as one-sided as the "dead money" line suggests.
What this tool does not do
It uses a single mortgage rate for the whole term, which understates the reality of remortgaging every two to five years. It uses a single investment return, which is a smoothed long-run assumption, not a forecast. It covers England and Northern Ireland stamp duty only: Scotland and Wales use LBTT and LTT respectively, and dedicated Scottish and Welsh rent-versus-buy tools are on the roadmap. It does not handle capital gains tax (your main home is exempt from CGT in the UK), income tax on investment returns outside an ISA, or the Help to Buy / Shared Ownership schemes.
Nothing on this page is financial advice. Treat the result as a conversation starter with a qualified UK mortgage broker or independent financial adviser.
Related calculators
Run these alongside for the full buying picture.
Common questions
How long do I need to own a home to make buying worthwhile?
In most realistic UK setups, the break-even year lands somewhere between five and ten. Upfront costs plus selling costs are heavy enough that short ownerships rarely beat renting once you account for the deposit's opportunity cost. The calculator shows your specific break-even year so you can see the line for your inputs.
What investment return should I assume on the deposit if I rent?
A global equity index has averaged around 5% to 7% real returns over long periods, but the range has been wide. The default is 5% nominal to stay on the conservative side. Use 3% if you'd hold cash or bonds, 7% if you'd go all-in on a global tracker and can stomach the volatility. Tax above the ISA allowance eats into these numbers in real life.
Does this include stamp duty?
Yes, using the 2025/26 England and Northern Ireland SDLT bands. First-time buyer relief applies up to a £500,000 purchase. Scotland's LBTT and Wales's LTT have different bands and are not handled here.
What about remortgaging at a different rate later?
The calculator uses one mortgage rate across the full term for simplicity. Most UK borrowers remortgage every two to five years, so try running the figures at both your current rate and a stressed higher rate to see how robust the verdict is.
Does it handle Scotland or Wales?
Not yet. SDLT is England and Northern Ireland only; Scotland uses Land and Buildings Transaction Tax (LBTT) and Wales uses Land Transaction Tax (LTT), both with different bands. Dedicated regional versions are on the roadmap.