UK mortgage and property calculators

Plan your deposit, mortgage and monthly repayments

Buying, moving or remortgaging, the numbers come down to three things: what you pay upfront, what you borrow and what it costs each month. These calculators work through each one using UK terms and pounds sterling.

Results are estimates, not mortgage offers. Every bank and building society applies its own lending criteria.

Which mortgage calculator do you need?

  • Mortgage repayments: start from a property price, deposit, rate and term.
  • Affordability: start from household income, outgoings and savings.
  • Remortgage: compare your current deal with a new one, fees included.
  • Deposit and LTV: see how much cash you need to reach a lower LTV band.
  • Home equity: find out how much of your home you own outright.

A monthly payment on its own only tells part of the story, so it’s worth running the same figures through two or three of them.

How to compare mortgage scenarios

1

Count all the upfront cash

The deposit is the biggest cost, not the only one. Budget for stamp duty or its Scottish and Welsh equivalents, solicitor fees, a survey, mortgage fees and removals, then keep an emergency fund on top.

2

Look at the whole monthly bill

Your mortgage payment is only one housing cost. Add Council Tax, buildings insurance, utilities and maintenance, plus service charge and ground rent if it’s a leasehold flat.

3

Try different rates and terms

Compare a few initial rates, the rate you’d move onto afterwards, and shorter and longer terms. A longer term lowers the monthly payment but adds interest overall.

4

Leave yourself some slack

A lender approving a loan doesn’t mean the payment will feel comfortable. Allow room for a drop in income, childcare, repairs or higher rates when your deal ends.

How mortgage repayments are worked out

On a repayment mortgage, the amount borrowed, the rate and the term set a fixed monthly payment. Each payment covers that month’s interest and pays off some of the loan. Early on, most of it goes on interest. As the balance falls, more of each payment clears the debt.

On an interest-only mortgage, you pay just the interest and still owe the full amount at the end, so you need a plan to repay it. Unless a calculator says otherwise, the tools here assume a repayment mortgage.

Deposit and loan-to-value (LTV)

LTV is your mortgage as a percentage of the property’s value. Borrow £240,000 on a £300,000 home and your LTV is 80%, with a £60,000 deposit before buying costs.

Lenders usually price their deals in LTV bands, often at 95%, 90%, 85%, 75% and 60%. Dropping into a lower band can cut your rate, so check how close you are to the next one. Don’t pour every penny into the deposit, though. You’ll still need cash for fees and emergencies.

Fixed, tracker and variable rates

A fixed rate usually lasts for a set deal period, often two or five years, not the whole mortgage. A tracker moves with the Bank of England base rate plus a set margin. Other variable rates can change at the lender’s discretion. When a deal ends, you normally move onto the lender’s standard variable rate unless you arrange a new one.

Most repayment calculators hold your rate steady for the full term, so run a second check at a higher rate to see what a rise would do.

Rate, APRC and fees

The initial rate sets your payment during the deal. The APRC shows the cost across the whole term, including fees and the rate you move onto afterwards. A low rate with a big product fee can cost more over a two-year deal than a slightly higher rate with no fee.

When comparing deals, line up the rate, product and broker fees, any cashback or free legal work, early repayment charges and the follow-on rate, and work out the cost over the time you expect to keep the deal.

Property tax depends on where you buy

Stamp Duty Land Tax applies in England and Northern Ireland. Scotland has Land and Buildings Transaction Tax and Wales has Land Transaction Tax. The bill depends on the price, whether you’re a first-time buyer and whether you already own property. Rates change, so check the current figure with HMRC, Revenue Scotland or the Welsh Revenue Authority.

Affordability is more than an income multiple

Lenders often cap borrowing at around four and a half times income, and a few go higher, but that’s only the starting point. They check your income, regular spending, credit commitments, dependants, age, deposit and the property itself, and usually test whether you could still pay if rates went up.

Set the estimated payment against your take-home pay and essential bills. What’s left should cover everyday spending, savings and the odd unexpected repair.

Remortgage or product transfer?

A product transfer is a new deal with your current lender. It’s usually quicker, often needs no new affordability check if you’re borrowing the same amount over the same term, and rarely involves legal work. Remortgaging means moving to a new lender. That can open up better rates, but expect a fresh application, a valuation and conveyancing.

Either way, add up any early repayment charge, exit fee, product fee, valuation, legal and broker costs, and take off any cashback. Be careful with term extensions: a lower monthly payment can hide a bigger total interest bill.

Overpaying your mortgage

Overpaying cuts your balance sooner, so you pay less interest overall. Most fixed and discounted deals let you overpay up to a set limit each year, often 10% of the balance, before early repayment charges apply. Check your mortgage terms first.

Equity and borrowing more

Your equity is the property’s value minus any mortgages secured on it. You can release some as cash through further borrowing from your lender, a remortgage or a second-charge mortgage, but all of it is secured on your home. Compare the monthly cost, total interest, fees and your new combined LTV first.

Think carefully before securing other debts against your home.

These calculators don’t give personal advice. For free, impartial guidance, visit MoneyHelper, or speak to an FCA-authorised mortgage adviser before you commit.

Your home may be repossessed if you do not keep up repayments on your mortgage.