1. Home
  2. Mortgages
  3. Mortgage Interest Rate Calculator
Published 16 August 2022
Reading Time
2 minutes

Mortgage Interest Rate Calculator

Use our mortgage interest rate calculator to estimate how much your repayments could change if interest rates fluctuate.

Written By

Many or all of the products and brands we promote and feature including our ‘Partner Spotlights’ are from our partners who compensate us. However, this does not influence our editorial opinion found in articles, reviews and our ‘Best’ tables. Our opinion is our own. Read more on our methodology here.

Mortgage interest rate calculator

Nerdwallet Logo Partner Spotlight

Mortgage Rates

NerdWallet has partnered with Koodoo to provide mortgage comparisons from the UK’s leading providers

Nerdwallet Logo Partner Spotlight

Get Fee-Free
Mortgage Advice

NerdWallet has partnered with L&C, the UK’s leading fee-free mortgage broker, to offer you expert advice

Think carefully before securing other debts against your home. Your home may be repossessed if you do not keep up repayments on a loan or any other debt secured on it.

How do I calculate the interest on my mortgage?

The way you calculate interest on a mortgage depends on the type of mortgage you have.

Interest on fixed-rate mortgages is calculated by multiplying the loan amount by the interest rate. This can be broken down into the annual or monthly interest for the mortgage.

For example, let’s say your mortgage loan amount was £150,000 with an interest rate of 2%:

The annual interest = £150,000 x 0.02 = £3,000.

The monthly interest = £3,000 ÷ 12 = £250.

Interest on variable rate mortgages is more difficult to forecast because it’s virtually impossible to predict how often interest rates, and therefore your repayments, will increase or decrease during your mortgage term.

Our mortgage interest rate calculator could help you estimate how changes to your mortgage interest rate may change your mortgage repayments. This information is intended as a guide only and relies on certain assumptions. Always speak to your current provider for details of how interest rate changes might affect your mortgage repayments before comparing deals from other lenders or brokers.

» MORE: Repayment Mortgage Calculator

Are mortgage interest rates calculated daily or monthly?

Most mortgage interest rates are calculated monthly. You can always check with your lender directly to confirm your mortgage details specifically

What happens if interest rates rise or fall?

Unless you have a fixed-rate mortgage deal, mortgage repayments could change if interest rates rise or fall. For example, if you have a variable rate mortgage, you may have to pay more if interest rates rise or less if interest rates fall. Tracker mortgages, discount mortgages and standard variable rate (SVR) mortgages are also likely to be affected by interest rate fluctuations.

Mortgage repayments can become more expensive if interest rates rise and cheaper if they fall – though interest rate fluctuations are not always passed on immediately to borrowers. Mortgage rates may change due to fluctuations in the Bank of England’s base rate or because of competition in the mortgage market.

Where can I find the best mortgage deals for me?

The easiest way to find the best deal for you is by comparing mortgages and mortgage lenders. Price comparison websites can help you quickly search through lots of deals to find the most suitable lender.

If you need expert advice on the best types of mortgage to apply for, speaking to an independent mortgage adviser may help. They’ll review your financial circumstances and help you find a mortgage deal.

» MORE: Check the latest mortgage rates

Useful links

Dive even deeper

Holiday Let Mortgages: Buying a Holiday Home to Rent Out

Holiday Let Mortgages: Buying a Holiday Home to Rent Out

A holiday let mortgage is used to buy property to rent out to paying guests. Buying a holiday let home can provide you with an income stream and certain tax benefits if you follow the rules.

When Can You Remortgage?

When Can You Remortgage?

It’s possible to remortgage whenever and how often you like, but there may be charges if you remortgage before your current deal ends.

How Long Does a Remortgage Take?

How Long Does a Remortgage Take?

The remortgaging process may take one to two months if you’re switching to a new lender, and maybe less than a week if you stay with your current lender.

Back To Top