About the Gift Aid Calculator
Gift Aid lets UK charities and community amateur sports clubs claim basic-rate tax back on donations from UK taxpayers: an extra 25p for every £1 you give. Your donation is treated as having been made after 20% tax, so a £100 gift becomes £125 for the charity. If you pay tax at a higher rate, you can claim the difference between your rate and the basic rate on the grossed-up donation through Self Assessment or your tax code.
This calculator shows the charity’s Gift Aid top-up, the extra relief you can reclaim at 40%, 45% or Scottish rates of 21%, 42%, 45% and 48%, and the net cost of your gift for the 2026/27 tax year. It also covers donors with income in the £100,000–£125,140 personal allowance taper, where grossed-up Gift Aid restores allowance and makes giving especially tax-efficient.
It assumes you have paid at least as much income tax or capital gains tax in the year as the charity claims (20% of the grossed-up gift); if you have not, HMRC can ask you to pay the shortfall. Scottish starter-rate (19%) taxpayers still give the charity the full 25% top-up but get no extra relief.
With the default inputs, the charity receives in total is £1,250.00. Change any value above to recalculate instantly.
How to use the gift aid calculator
- 1Enter how much you are giving to the charity.
- 2Choose the highest rate of income tax you pay, including the Scottish rates.
- 3Read how much the charity receives with Gift Aid.
- 4Note the relief you can claim back and the net cost of your gift.
Formula and method
Gift Aid treats your donation as a payment made out of income already taxed at the 20% basic rate. The charity reclaims that 20% of the grossed-up amount, which equals 25p for every £1 donated. A higher or additional rate taxpayer can claim the difference between their own rate and 20% on the gross donation, because the gift extends their basic-rate band by the gross amount.
For income in the £100,000–£125,140 taper, the gross gift also reduces adjusted net income and restores allowance, giving an effective 60% rate (67.5% in Scotland). The relief figure here assumes your whole gross gift falls within the band you choose; a large gift that drops you into a lower band would get a little less.
- gross
- Donation plus basic-rate tax reclaimed by the charity
- rate
- Your marginal income tax rate
Worked examples
£1,000 from a higher-rate taxpayer
Gross gift is £1,000 ÷ 0.8 = £1,250, so the charity claims £250. As a 40% taxpayer you reclaim 20% of £1,250 = £250, making the gift cost £750.
£100 from a basic-rate taxpayer
The charity gets £125 — your £100 plus £25 of Gift Aid. Basic-rate taxpayers have no extra relief to claim.
£4,000 from someone earning £110,000
The £5,000 gross gift cuts adjusted net income to £105,000, restoring £2,500 of allowance (worth £1,000) on top of £1,000 of higher-rate relief. The charity receives £5,000 and the donor’s net cost is only £2,000.
Frequently asked questions
How much does Gift Aid add to a donation?+
Gift Aid adds 25p for every £1 you donate, because the charity reclaims basic-rate tax of 20% on the grossed-up gift. A £10 donation becomes £12.50 and a £100 donation becomes £125.
How do higher-rate taxpayers claim Gift Aid relief?+
Enter your total Gift Aid donations (the amount you actually gave) on your Self Assessment tax return, or ask HMRC to adjust your tax code. HMRC gives relief of 20% (40% taxpayers) or 25% (45% taxpayers) of the grossed-up gift.
What if I don’t pay enough tax for Gift Aid?+
You must pay at least as much income tax and capital gains tax in the tax year as all your charities reclaim. If you do not, HMRC can ask you to pay the difference, so non-taxpayers should not tick the Gift Aid box.
Can I carry back Gift Aid to the previous tax year?+
Yes. You can ask for donations made in the current tax year to be treated as made in the previous one, as long as you make them before you send that previous year’s return and by its 31 January deadline. This helps if your rate was higher last year or you want relief sooner.
Does Gift Aid reduce adjusted net income?+
Yes. Grossed-up Gift Aid donations are deducted when working out adjusted net income, so they can reduce the High Income Child Benefit Charge and restore personal allowance lost in the £100,000–£125,140 taper.
Tax results are estimates based on published rules and simplified assumptions. They are not tax advice — check official guidance or a tax professional for your situation.