Capital gains tax
The £3,000 exemption, how gains stack on your income, and the 18%/24% split — with every assumption editable.
Gains are stacked on top of your income.
Gains are stacked on top of your income. Whatever basic-rate band you have not used with income is available to gains at 18%; anything above the higher-rate threshold is taxed at 24%. The annual exempt amount and any losses come off first.
Timing matters more than most people expect: spreading a disposal across two tax years, or realising gains in a low-income year, can move a chunk from 24% to 18% or to nothing.
Formula
tax = min(gain − AEA − losses, headroom) × 18% + remainder × 24%
headroom = basic-rate band − taxable income. Personal allowance tapers above £100,000.
- 012024/25 onward rates: 18% and 24% for all assets; residential property no longer differs.
- 02Annual exempt amount £3,000; check the current figure.
- 03Ignores Business Asset Disposal Relief, spouse transfers and carried-forward losses beyond the figure entered.
- 04Scottish income tax bands do not apply to CGT; UK thresholds are used.
Holding everything else at your inputs
Each row changes one variable and shows the result. It illustrates which assumptions the answer is most sensitive to — it does not suggest which to choose.
| Variable | Changed to | CGT due | vs your result |
|---|
Reminder: this tool is general education. It doesn't know your circumstances and isn't a personal recommendation or tax advice. For decisions, consult an accountant or FCA-authorised adviser — our toolkit shows how to find one.