Use the fields above to estimate potential tax savings over a year.
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.
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 2026/2027 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 –
Sophie Barber
Communications Manager
More guides on Finder
-
Lloyds Upfront Interest review
Discover who is most suited to this unique product with our review of Lloyds’ Upfront Interest savings account.
-
Best savings accounts for November 2026
Find out more about the different types of savings accounts on offer.
-
Compare savings accounts with compound interest
We look at the definition of compound interest, what it concretely means and how you can use it to grow your savings more quickly.
-
Best easy & instant access savings accounts UK 2026
Earn interest on your savings while still being able to withdraw them if you need to with an easy access savings account.
-
What is annual equivalent rate (AER)?
The AER, or Annual Equivalent Rate, is the official rate for savings accounts. It’s designed to allow easy comparisons between accounts.
-
Best Virgin Money savings account rates compared
Thinking about getting a savings account with Virgin Money? We look at the options, from cash ISAs to regular savings accounts, plus pros and cons.
-
Lloyds Bank’s top savings rates get… rated
Looking to save with Lloyds bank? Our guide explains the different savings account options, so you can decide which is the best saver for you.
-
Cash ISA vs savings accounts: Which is better?
Choosing between ISAs or normal savings accounts is easier than it seems. Pick the one which pays out most! Read our guide for tips on how to get the most out of your savings pot.
-
Best cash ISA rates UK 2026
A cash ISA is a savings account where you never pay tax on the interest. Use our comparison table to find the best ISA rates – whether you want to lock cash in for a set time or keep it easy access.
-
Compare high interest & high yield savings accounts
Kickstart your savings plan with a high interest savings account.

