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Gift Aid Calculator (2026/27)

Updated for the 2026/27 tax year
Work out the real value of a Gift Aid donation in 2026/27 — not just the charity's 25% top-up, but your own higher/additional-rate relief and the knock-on effects on your Personal Allowance and Child Benefit charge. Unlike calculators that look at Gift Aid alone, this figure is calculated as part of your whole tax position.

The basic mechanic

When you make a Gift Aid donation, the charity reclaims basic-rate tax on it: your £1 becomes £1.25 in the charity's hands (it reclaims 20% on the gross). That part happens automatically — you don't need to do anything to give the charity its top-up.

Higher and additional-rate relief

If you pay tax above the basic rate, you can claim back the difference yourself through Self Assessment (or a tax-code adjustment):

This is money that stays with you — it doesn't affect what the charity receives.

The part almost no calculator shows: your adjusted net income

A Gift Aid donation reduces your adjusted net income, and that can be worth far more than the headline rate:

MyTaxReality runs your donation through the same engine that knows your Income Tax, Personal Allowance taper and Child Benefit charge — so it shows the relief you'll actually get, including the effects a Gift-Aid-only calculator can't see.

Carry-back election

You can elect to treat a donation made this tax year as if you made it in the previous one, as long as you make the election by the Self Assessment filing deadline and had paid enough tax in that earlier year. It's a useful lever if you paid at a higher rate last year, or want the adjusted-net-income benefit applied to the earlier year's position.

Want to see how this donation moves your whole tax position?

See how this donation affects your whole tax position →