Tax on savings interest calculator UK

Savings interest rates can quickly change, and while high interest rates are great for building your rainy day fund, you might pay tax on interest.

Our savings tax calculator helps you understand how much tax you pay on interest earned and how much you could save if you moved some from your regular savings account to a cash ISA.

Use the fields above to estimate potential tax savings over a year.

Compare cash ISAs

How does our calculator work?

1. Enter your income tax bracket. You can find a summary of the brackets below!

2. Enter your current savings pot, not including ISAs.

3. Enter the amount you plan to add to your savings pot each month.

4. Enter the interest rate of your savings pot and press calculate. If you have more than one savings account, take the average.

What does the result mean?

Our calculator shows how much tax you will currently pay on your savings over a year. It also shows how much you could save by moving a certain amount to an ISA (within your ISA allowance).

If you are not currently paying tax on your savings, the calculator will let you know. If this is the case for you, you don’t need to move your savings to an ISA unless it offers you a better interest rate.

What are the UK income tax brackets?

Basic rate: Annual income of £12,571 to £50,270. You pay income tax of 20%.
Higher rate: Annual income of £50,271 to £125,140. You pay income tax of 40%.
Additional rate: Annual income from £125,141. You pay income tax of 45%.

What is the personal savings allowance?

For the 2024/2025 tax year, the personal savings allowance is as follows:

Basic-rate taxpayers: Earn up to £1,000 in interest on savings per year without paying tax.
Higher-rate taxpayers: Earn up to £500 in interest on savings per year without paying tax.
Additional-rate taxpayers: There is no personal savings allowance, so you will be taxed on all savings interest.

How many people have an ISA?

According to a 2025 Finder survey, almost a third of Brits (31%) currently has an ISA – whether that’s a cash ISA or a stocks and shares ISA. This equates to around 16.8 million people.

What are the tax benefits of an ISA?

Our personal savings allowance calculator shows whether you could benefit from moving some of your savings into an ISA. This will be the case if you earn more interest than your personal savings allowance and are therefore paying tax.

When interest rates are high, it can be easier to go over your personal savings allowance, so you might want to consider an ISA.

Click here for more research. For all media enquiries, please contact –

Matt Mckenna
UK Head of Communications
T: +44 20 8191 8806

Thank you for your feedback!

To make sure you get accurate and helpful information, this guide has been edited by Holly Jennings as part of our fact-checking process.

Written by

Chris Lilly

Head of publishing

Chris Lilly is Head of publishing at finder.com. He's a specialist in personal finance, from day-to-day banking to investing to borrowing, and is passionate about helping UK consumers make informed decisions about their money. In his spare time Chris likes forcing his kids to exercise more. See full bio

Chris's expertise

Chris has written 566 Finder guides across topics including:

Loans & credit cards
Building credit
Financial health
Share trading

Co-written by

Matthew Boyle

Publisher

Matthew Boyle is a banking and mortgages publisher at Finder. He has a 7-year history of publishing helpful guides to assist consumers in making better decisions. In his spare time, you will find him walking in the Norfolk countryside admiring the local wildlife. See full bio

Matthew's expertise

Matthew has written 279 Finder guides across topics including:

Helping first-time buyers apply for a mortgage
Comparing bank accounts and highlighting useful features
Publishing easy-to-understand guides

Charter Savings Bank savings accounts review Compare the best ISA rates for over-60s UK 2025

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