Loading page
Estimate your net position after capital gains tax if you keep a rental and sell later, or sell now and invest.
Keep: net position after CGT
£224,096.49Estimate for your 100% share, selling on 14 October 2031Sell: net position after CGT
£155,466.34Estimate after investing for 5 yearsKeeping for 5 years leaves an estimated £224,096.49 for your share after CGT; selling on 14 October 2026 and investing the rest gives £155,466.34.
Sale on 14 October 2031: 2026/27 rates assumed for a later tax year. Gain on your share £147,782.22.
Sale on 14 October 2026: 2026/27 rates. Gain on your share £100,000.
Example figures.
Rates as of
This calculator compares two paths for a rental you own: keep it for a number of years and then sell, or sell now and invest what is left. It uses the current value, loan, annual rent and costs for the whole property, your growth and return assumptions and the comparison period. It then estimates capital gains tax (CGT) on each sale from your cost, purchase date, ownership share and income.
The keep path grows today's value each year, subtracts the unchanged loan and adds rent less costs, held as cash. CGT on selling at the projected value is then deducted from your share. The sell path takes today's value less the loan, deducts CGT on selling today and compounds the rest at your return.
CGT reuses this site's UK capital gains calculation: your share of the gain, less the annual exempt amount, taxed at 18% within your unused basic-rate band and 24% above it.
The formulas keep exact fractions and round the final money to the nearest penny, so small display differences do not compound.
Take a property worth £300,000 with a £150,000 loan, £18,000 of rent and £6,000 of costs a year, 3% growth, a 4% return and five years. For this illustration only, assume a cost of £200,000 from 1 June 2016, full ownership and other taxable income of £20,000.
Selling on 14 October 2026 gives a £100,000 gain and estimated CGT of £22,218, so £127,782 is invested and grows to £155,466.34. Keeping until 14 October 2031 gives a projected value of £347,782.22, a £147,782.22 gain and estimated CGT of £33,685.73 at 2026/27 rates, leaving £224,096.49. Keep less sell is £68,630.15.
Both paths are simplified. Rent and costs stay constant, the loan is never repaid and the rent surplus earns nothing. Income tax on rent, sale costs, investment fees, inflation and tax on the investment's returns are excluded. Growth and return are your assumptions, not forecasts. The result is an estimate, not a recommendation to keep or sell.
CGT assumes an individual resident taxpayer with no other gains, losses or reliefs, and the same other income in the year of each sale. Results are for your ownership share, assuming the loan, rent and costs are shared in the same proportion. If a sale would not cover the loan and the CGT, the sell path shows a shortfall that is not compounded.
Rates for tax years after 2026/27 are not yet published, so a later sale assumes the 2026/27 rates, basic-rate band and £3,000 exemption continue. Private Residence Relief, other reliefs and non-resident rules are outside this comparison.
GOV.UK explains that your gain is usually the difference between what you paid for the property and what you sold it for. You can deduct costs of buying, selling or improving it, but not normal maintenance. If you own it jointly, you work out the gain on your share. For 2026/27 the tax-free allowance is £3,000; the rest is taxed at 18% within your unused basic Income Tax band and 24% above it.
Ask an accountant or tax adviser to confirm the cost base, the tax on selling now and on a later sale, and any reliefs you may be entitled to. Bring purchase records, improvement invoices, ownership details and income information. Ask a financial adviser about the alternative investment's risks and costs. Company or trust ownership, a former home, overseas residence or a loan being repaid over time need particular care.
No. It estimates your net position after Capital Gains Tax for keeping and for selling now, from your own assumptions and tax facts. It does not rank the options or allow for your wider circumstances, risk or the income tax on rent. Use the figures as one input before speaking to an adviser.
Selling now uses today’s date and the current value; keeping sells at the projected value at the end of your period. Both use the GOV.UK method: the gain on your share, less the £3,000 annual exempt amount, taxed at 18% within your unused basic-rate band and 24% above it. Later tax years assume the 2026/27 rates continue.
No. You enter both assumptions. Each compounds once a year at a constant rate, which does not model changing markets, volatility, inflation or investment fees. Negative rates are accepted down to minus 100%.
Enter annual running costs and interest, excluding loan principal repayments, sale costs and taxes. The loan balance stays unchanged. A repayment mortgage or changing borrowing costs needs a separate cash flow calculation.
Selling then needs extra funds, so the sell result shows a shortfall rather than a compounded balance. The same applies when the tax on selling now is larger than your share of the equity. The keep result can still be negative.
Estimate your property gain, tax and 60-day reporting deadline.
See what remains after running costs, mortgage payments and income tax.
