UK Gift Aid Calculator
See how much extra your charity can claim, and estimate your personal tax relief if you are a higher-rate or additional-rate taxpayer.
This calculator is for illustration only and uses standard Gift Aid assumptions currently used in the UK (charity reclaims 25p for each £1 donated).
What is Gift Aid?
Gift Aid is a UK tax relief that allows charities and Community Amateur Sports Clubs (CASCs) to claim an extra 25% on eligible donations made by UK taxpayers. If you donate £100, the charity can usually claim another £25 from HMRC, making the total value of your donation £125.
It is one of the simplest ways to increase the impact of your giving without increasing the amount leaving your bank account.
How this Gift Aid calculator works
1) Charity top-up amount
For eligible donations, the charity can reclaim basic rate tax. The common rule of thumb is:
- Charity top-up = Your donation × 25%
- Total to charity = Your donation × 125%
2) Extra tax relief for higher/additional-rate taxpayers
If your highest tax band is above basic rate, you may be able to claim additional relief through Self Assessment (or by asking HMRC to adjust your tax code). This relief is based on the grossed-up donation amount.
- Gross donation = net donation ÷ 0.8 (or × 1.25)
- Extra relief = gross donation × (your rate − 20%)
In practical terms, higher-rate and additional-rate taxpayers can often reduce the real after-tax cost of giving.
Worked examples
Example A: One-off £80 donation (basic-rate taxpayer)
- You donate: £80
- Charity claims Gift Aid: £20
- Total reaching charity: £100
- Your additional personal tax relief: £0
Example B: Monthly £50 donation (higher-rate taxpayer)
- Annual donation: £600
- Annual Gift Aid to charity: £150
- Total annual value to charity: £750
- Estimated personal tax relief: £150
- Estimated effective annual cost after relief: £450
Important rules to remember
- You must have paid enough UK Income Tax and/or Capital Gains Tax in the tax year to cover the Gift Aid amount charities reclaim on your donations.
- Donations must be your own money (not from a company, collection, or someone else).
- You should keep records of donations and Gift Aid declarations.
- Tax rules can change, and special cases may apply.
When a Gift Aid calculator is especially useful
- Planning regular giving and setting donation budgets
- Comparing one-off vs monthly donations
- Preparing your Self Assessment tax return
- Checking how much support your chosen charity actually receives
Frequently asked questions
Does Gift Aid cost me more money?
Not directly. The charity gets more from HMRC based on your donation. If you are a higher or additional-rate taxpayer, you may also be able to claim extra tax relief personally.
Can I add Gift Aid to every donation?
No. Some donations are not eligible (for example, where you receive significant benefits in return). The charity can usually tell you whether your donation qualifies.
Do I need to fill in a tax return to claim extra relief?
If you already file Self Assessment, include your Gift Aid donations there. If you do not, you may be able to contact HMRC to adjust your tax code, depending on your situation.
Final thoughts
A Gift Aid calculator helps you make smarter giving decisions. Whether you give once a year or every month, understanding the tax mechanics means your support can go further. Use the calculator above, test a few scenarios, and keep clear records so both you and your charities get the full benefit available.