Rates & sources
UK tax rates and thresholds, as published by HMRC. Scotland and Wales have devolved rates for income tax and property transactions.
Source: HMRC — Tax rates — figures refreshed at the start of each tax year.
When to use this calculator
- Before accepting a pay change, bonus, pension contribution, or salary-sacrifice option.
- When you want to compare employed, self-employed, or dividend-based income scenarios.
- When you need a simple take-home estimate before running payroll or filing returns.
- When you are approaching the £100,000 income level and want to understand the personal allowance taper effect.
- When you are planning a salary sacrifice arrangement and need to see the net pay impact before agreeing terms.
A realistic South Africa planning example
Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.
Proceeds from Sale (R)
2000000
Base Cost (original cost + improvements) (R)
R500
Other Taxable Income (R)
R400,000
Asset Type
Shares / unit trusts
After entering these figures, review capital gain, primary residence exclusion and taxable gain (40% inclusion) together rather than in isolation — each metric tells a different part of the story. Then rerun the tool with one input adjusted to see which variable has the biggest effect on all three outputs before you settle on a plan.
How to read your results
Capital Gain
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Primary Residence Exclusion
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Taxable Gain (40% inclusion)
Review this figure alongside your gross income so you can understand the true cost of deductions and plan around any thresholds before the tax year closes. If the figure looks higher than expected, check whether any pension or gift-aid contributions could reduce your taxable income.
CGT Payable
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Effective Rate
The effective rate lets you compare options on a true like-for-like basis rather than being misled by different compounding periods or fee structures. Use it to cut through headline marketing rates when shortlisting providers or products.
Net After Tax
Review this figure alongside your gross income so you can understand the true cost of deductions and plan around any thresholds before the tax year closes. If the figure looks higher than expected, check whether any pension or gift-aid contributions could reduce your taxable income.
Method & assumptionsAuthoritative sources
South Africa's capital gains tax (CGT) is not a standalone tax — it is incorporated into your normal income tax assessment by SARS each year. When you dispose of a capital asset at a profit, you calculate the gross capital gain by subtracting the base cost from the proceeds. From this you deduct any applicable exclusions: the R2 million primary residence exclusion if the property was your main home, and the R40,000 annual exclusion that every individual receives. The remaining net gain is then multiplied by the 40% inclusion rate, and this included gain is added to your other taxable income for the year. Your marginal income tax rate — determined by the 2024/25 SARS brackets — is applied to the combined total, and the difference between the tax on your total income and the tax on your income without the gain represents your CGT liability.
This calculator models the full marginal tax impact across all seven SARS brackets, from 18% on income up to R237,100 to 45% on income exceeding R1,817,000. It is designed for individual taxpayers only; trusts and companies face different inclusion rates and flat tax rates not covered here. The effective rate shown divides CGT payable by the raw capital gain, giving you a useful single-figure summary of your tax burden on the disposal. Always retain purchase agreements, improvement invoices, and transfer documents as SARS may request proof of your base cost during a verification. For large or complex disposals, consult a registered tax practitioner before filing your ITR12.
Common mistakes
- !Entering gross income when you really want take-home pay, or vice versa.
- !Ignoring pension contributions, deductions, or local tax rules that change the result.
- !Comparing monthly and annual figures without standardising them first.
- !Overlooking the National Insurance threshold changes that apply mid-year when rates or bands are adjusted in a Budget.
- !Assuming a salary sacrifice benefit reduces take-home pay by the full gross amount, rather than only the after-tax cost.
What to do next
- Check the same scenario with related pay or deduction calculators to see the full picture.
- Keep a copy of the assumptions you used so you can compare next tax year or pay period accurately.
- Read the related guides below if you are choosing between multiple income or deduction options.
- If you are self-employed, run the self-employment tax calculator alongside this result to compare the net position against employed income.
- Check whether increasing your pension contribution by even one or two percent changes the take-home significantly — use the pension calculator next.
Frequently asked
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End-of-article next steps
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