Gain and tax bridge
How the gross gain is reduced by losses and allowance before the CGT estimate.
Amount
Capital Gains Tax Calculator
Model a UK Capital Gains Tax estimate across disposals of investments, residential property, or qualifying business relief gains using selectable tax-year assumptions.
Estimated CGT£6,3782026/27 across 1 disposal
Taxable gain£28,500After losses and £3,000 allowance
After-tax position£25,12220.2% effective rate on listed gains
CGT rate split
The taxable gain split across basic, higher, or relief-rate CGT treatment.
Taxable gain
Gain by disposed asset
Each listed disposal shown as your share of gain or allowable loss.
GainLoss
Tax by asset type
Estimated CGT split by asset-rate category after the simplified allocation.
Estimated CGT
Disposed assets
Asset 1investment or other asset; your proceeds £75,000; allowable costs £43,500£31,500
Tax year gains
Number of disposals1
Your share of disposal proceeds£75,000
Listed gains before losses£31,500
Losses from listed disposals£0
Net gain or loss from listed disposals£31,500
Losses and allowance
Current-year losses availableLosses from listed disposals plus other same-year losses£0
Current-year losses used£0
Brought-forward losses used£0 left unused in this estimate£0
Total losses used£0
2026/27 annual exempt amount£3,000
Annual exempt amount available£0 already used£3,000
Taxable gain after allowance£28,500
CGT estimate
Taxable income before gainsAfter Personal Allowance and reliefs£30,000
Basic-rate band remaining£7,700
Gain taxed at basic CGT rate£7,700
Gain taxed at higher CGT rate£20,800
Gain taxed at relief rate£0
Estimated Capital Gains Tax22.4% effective rate on taxable gain£6,378
Rate allocation
investment or other asset£28,500 taxable; £7,700 basic, £20,800 higher, £0 relief£6,378
Reporting checks
Your share of disposal proceeds£75,000
Self Assessment proceeds thresholdFor 2023/24 onwards£50,000
Proceeds threshold checkMay need reporting if in Self Assessment
Tax due checkTax estimated
Assumptions
Calculation notes
- Uses the selected 2026/27 annual exempt amount and Capital Gains Tax rates.
- Taxable income before gains should be income after Personal Allowance and Income Tax reliefs, before adding these gains.
- Gains and losses are aggregated across listed disposals for the selected tax year.
- Current-year losses are deducted from same-year gains before the annual exempt amount. Brought-forward losses are then used only to reduce remaining gains down to the available annual exempt amount.
- Where mixed asset types are listed, the model allocates reductions to higher-rate gains first for a practical planning estimate.
- Does not model spouse transfers, private residence relief, lettings relief, chattels rules, EIS/SEIS reliefs, non-resident property reporting, foreign income and gains regime, carried interest, crypto pooling, share matching, or HMRC payment deadlines.
- This is a planning estimate, not tax advice.
Guide
How to use the Capital Gains Tax Calculator
Model a UK Capital Gains Tax estimate across disposals of investments, residential property, or qualifying business relief gains using selectable tax-year assumptions. It is useful for comparing personal finance scenarios before making a bigger decision because it keeps inputs, charted outputs, notes, and related next steps on the same page.
Start by checking cgt rules year, disposed assets, other losses this tax year, unused losses brought forward, annual exempt amount already used, and taxable income before gains. Where rule years are available, choose the rules year that matches the scenario you are checking. The results update as assumptions change, so you can compare scenarios before downloading a CSV report.
If rules, tax years, thresholds, or eligibility assumptions affect the result, review the calculation notes before acting on the output.
Inputs
Inputs to check
- CGT rules year: Choose the current UK tax year or one of the previous four.
- Disposed assets: Add each disposal in the selected tax year
- Other losses this tax year: Enter the value you want to test.
- Unused losses brought forward: Enter the value you want to test.
- Annual exempt amount already used: Use this if other gains have already used some or all of your allowance
- Taxable income before gains: Income after Personal Allowance and reliefs, before adding this gain
FAQs
Capital Gains Tax Calculator FAQs
What is the Capital Gains Tax Calculator for?
Model a UK Capital Gains Tax estimate across disposals of investments, residential property, or qualifying business relief gains using selectable tax-year assumptions. Use it when you want a quick, editable estimate with charted results and visible assumptions.
Which assumptions should I check first?
Start with cgt rules year, disposed assets, other losses this tax year, unused losses brought forward, annual exempt amount already used, and taxable income before gains. Then confirm the selected rules year matches the period you are modelling.
Are the results exact?
The result is a planning estimate, not financial advice. Tax, payroll, pension, investment, mortgage, and allowance rules can depend on personal circumstances.
Can I keep or compare the result?
Yes. Use the Download CSV button on the calculator page to export the current inputs, headline results, detailed rows, chart data, insights, and notes.
What should I try next?
Try Compound Growth Calculator, ISA Calculator, FIRE Calculator, and Rental Yield Calculator next. These tools are linked because they use related assumptions or answer the next practical question.