Savings Interest Tax Calculator
Estimate how much tax may apply to savings interest. Enter other income and taxable interest so the calculator can consider the available allowances and the tax bands that apply to savings.
Calculation breakdown
How to use this tool
- Choose the tax year and enter other taxable income.
- Add your share of taxable interest and identify ISA interest separately.
- Review taxable interest, estimated tax and interest remaining after tax.
How the result is calculated
Savings allowances depend on your wider income. Interest can move you across a band, so the calculation considers the full income stack rather than applying one fixed tax rate to every pound.
Worked example
In a simplified example, £1,200 interest with £1,000 of available allowance and a 20% tax rate on the rest produces £40 of tax. Other allowance interactions can change this.
What this result does not cover
This is an estimate for the supported income types, not a complete tax return. Overseas income, trusts and unusual tax situations need separate treatment.
Questions people ask
Does ISA interest use my savings allowance?
No. Keep qualifying ISA interest outside taxable interest.
How do I enter a joint account?
Enter only your share under the applicable ownership treatment.
Can a pay rise affect savings tax?
Yes. Wider income can change your band and allowance.
Supported scope and official sources
2026/27 savings and non-savings income only. Enter gross income before the personal allowance, not an amount already reduced by it. No dividends or overseas income.
- www.gov.uk — apply tax free interest on savings
- www.gov.uk — income tax rates
- www.gov.uk — scottish income tax
Source snapshot: 21 October 2026. Independent specialist review is pending. Calculations do not confirm eligibility or replace official decisions.