Key points
- On a £300,000 home with a 25% deposit you need £75,000 up front, plus no stamp duty as a first-time buyer (£5,000.00 if you are moving home).
- The mortgage would cost £1,332.43 a month over 25 years at the average 2-year fixed rate of 5.13%.
- Lenders often lend about 4.5 times income, so that mortgage needs around £50,000 of household income.
- Budget for fees too: legal work, a survey, mortgage fees and moving.
Work out your own
Put in your income and deposit to see the price you could afford, then the mortgage and stamp duty.
How much can I borrow?What you need up front
- A deposit: the part of the price you pay yourself. Many lenders accept 5% or 10%, but the best rates usually need 25% or more.
- Stamp duty: in England and Northern Ireland, nothing on the first £125,000 for home movers and £300,000 for first-time buyers. Scotland and Wales have their own taxes: see stamp duty across the UK.
- Fees: legal work (conveyancing), a survey, any mortgage arrangement fee and moving costs.
The costs at three prices
With a 25% deposit and a 25-year repayment mortgage at 5.13%, the Bank of England's average 2-year fixed rate at 75% loan-to-value (September 2026):
| Price | Deposit | Stamp duty, first home | Stamp duty, moving | Mortgage a month | Income at 4.5× |
|---|---|---|---|---|---|
| £250,000 | £62,500 | £0.00 | £2,500.00 | £1,110.35 | £41,667 |
| £300,000 | £75,000 | £0.00 | £5,000.00 | £1,332.43 | £50,000 |
| £400,000 | £100,000 | £5,000.00 | £10,000.00 | £1,776.57 | £66,667 |
Stamp duty for England and Northern Ireland. Income is the household income a lender lending 4.5 times income would look for.
What you pay each month
Your mortgage payment is the biggest monthly cost, but not the only one. Add Council Tax, buildings insurance (usually required by your lender), energy and upkeep. Rates change: at the average revert-to rate of 6.58%, the £300,000 example would cost £1,530.48 a month.
Fees and other costs
Fees vary a lot between firms and homes, so get quotes rather than relying on averages. Ask for a fixed fee for conveyancing, check what the lender's valuation covers, and compare mortgage deals on the total cost, including fees, over the fixed period. The remortgage calculator compares deals with fees included.
Bottom line
The deposit is the biggest cost up front, but stamp duty and fees can add thousands. Work out all three before you start viewing, and check your monthly payment at a higher rate too, since your fix will end.
Tips
- A bigger deposit usually gets a lower interest rate: lenders price by loan-to-value.
- First-time buyers in England pay no stamp duty up to £300,000, as long as the price is £500,000 or less.
- Check the Council Tax band of any home you look at: it is a cost every month.
This guide explains the rules; it is not personal financial advice.