Buy vs Rent + Invest Calculator
A realistic side-by-side comparison of buying versus renting + investing, including transaction costs, maintenance and the opportunity cost of your deposit.
Your buy vs rent verdict
Add your rent, the property price and how long you'd stay — then open the assumptions for a tighter answer.
How it works
This calculator compares the total net wealth you'd hold after a set number of years if you bought a home versus if you rented and invested the difference. It's the financial version of the question most people ask the wrong way round — instead of "is my mortgage cheaper than the rent?", it asks "where do I end up after fees, maintenance and the lost return on my deposit?"
It matters because the monthly comparison flatters buying. Buying carries large one-off costs (stamp duty, legal fees, surveys), ongoing maintenance, and the opportunity cost of locking a deposit into a single illiquid asset. Renting carries rent inflation, no equity build-up, and no exposure to house-price growth. Each side has hidden numbers; this tool lines them up.
It's most useful for first-time buyers weighing whether to stretch for a deposit now, owners considering a downsize-and-invest, and anyone whose job or relationship status could change inside the next five years. It's least useful as a forecast — small shifts in mortgage rates, house-price growth or investment returns can flip the answer.
A worked example
Take a £300,000 home with a 10% deposit at a 5% mortgage rate over 25 years, against rent of £1,400/month, both modelled over 10 years. The buyer's true cost is interest + stamp duty + ~1%/yr maintenance + selling fees — not the full monthly payment, because principal becomes equity. The renter's wealth grows by investing the £30,000 deposit plus any monthly difference at, say, 5%. After 10 years the two sit within touching distance — and which one wins is decided almost entirely by house-price growth and how long you stay.
Why this matters
The honest answer to "should I buy or rent?" is rarely about the maths alone — but knowing the maths stops you making a decision purely on feel. Buying tends to win on long horizons (10+ years) and in rising markets. Renting tends to win when you might move, when transaction costs are very high, or when you can genuinely invest the difference rather than spend it. Use the result as a starting point for that conversation, not a verdict.
Common mistakes
- Treating the entire mortgage payment as a "cost" — most of the principal is forced saving.
- Forgetting stamp duty, legal fees, surveys and selling agent fees on the buying side.
- Ignoring rent inflation on the renting side — rent rarely stays flat for a decade.
- Assuming the deposit would actually be invested rather than spent if you rented.
- Using a single optimistic house-price growth number and treating the output as a forecast.
Beyond the numbers
Money is one input. The others rarely show up in a spreadsheet but often decide the answer: flexibility to move for work, who handles the boiler at midnight, whether you'd genuinely enjoy decorating a place that's yours, and the psychological weight of a 25-year mortgage versus a 12-month tenancy. A confident renter and a confident owner can both be right; what matters is matching the choice to the life you actually live in the next five to ten years. If a stretched purchase would block other goals — pension, career change, starting a family — the cheaper-looking option on the calculator may not be the cheaper one in practice.
Related tools: Mortgage Calculator · House Deposit Calculator · Stamp Duty Calculator · Mortgage Affordability
Frequently asked
Complete Guide
Rent vs Buy in the UK: Key Financial Considerations
The 'renting is dead money' line is one of the most repeated phrases in UK personal finance — and one of the most misleading. Whether buying or renting works out better for you depends on your deposit, how long you plan to stay, mortgage rates, and what you'd do with the money you didn't tie up in a home.
What renting really costs
When you rent, you pay for somewhere to live and the flexibility to move. You don't pay buildings insurance, major repairs, or stamp duty, and you can leave at the end of a tenancy without estate agent fees.
The trade-off is that your housing costs can rise at renewal, and you're not building any equity in the property.
What buying really costs
A mortgage payment is only part of the cost of owning. You'll also have stamp duty, legal fees, surveys, buildings insurance, maintenance, service charges (on leasehold flats), and sometimes ground rent.
Over a 25-year mortgage you'll typically pay a significant amount in interest on top of the price of the home — which is why overpayments, when affordable, can be so powerful.
The break-even question
Buying tends to win financially the longer you stay put, because the upfront costs (stamp duty, fees, moving) get spread over more years. As a rough guide, if you might move within 3–5 years, renting often comes out ahead once costs are honest.
Our rent vs buy calculator lets you compare the realistic monthly cost of each, factoring in the deposit you'd otherwise invest.
Beyond the spreadsheet
Money isn't the only factor. Owning gives you security of tenure and the freedom to decorate; renting gives you flexibility to follow work or relationships without selling up.
There's no universal right answer — only the one that fits your life and your numbers today.