Capital Gains Tax Calculator for Selling a Rental Property
Estimate the Capital Gains Tax due when you sell a property you let out. Enter what you paid, what it cost to buy, improve and sell, any reliefs you have already worked out, and your other taxable income. The calculator works out the gain, takes off the annual exempt amount, stacks what is left on top of your income, and shows how much falls at each rate.
Your figures stay in your browser: nothing you type is sent to us or stored. We count only that the page was opened and that a calculation was run — how we count.
Current rates only. This calculator uses the rates and allowance for the tax year 2026 to 2027, for an individual selling UK residential property. It does not work out Private Residence Relief or lettings relief: you enter the amount of each relief from your own calculation.
How Capital Gains Tax on a rental property is worked out
Capital Gains Tax is charged on the profit you make when you sell, or otherwise dispose of, a property that is not your home. For most landlords that means a buy-to-let. It is worked out in five steps.
1. The gain
Start with the sale price and take off the costs of selling, such as estate agents' and solicitors' fees. From that, take off what the property cost you: the purchase price, the costs of buying it, and the cost of capital improvements, meaning work that added to the property, like an extension, rather than repairs and decorating. What is left is the gain. If it is negative, you made a loss and no tax is due on this sale.
2. Reliefs
If you lived in the property as your main home at some point, Private Residence Relief can remove part of the gain, and in some cases lettings relief can remove more. These reliefs depend on exactly when you lived there and when you let it, so this calculator does not work them out: enter the amount of gain each one removes, from your own or your adviser's calculation. Reliefs cannot take the gain below zero.
3. The annual exempt amount
Every individual can make £3,000 of gains in the tax year 2026 to 2027 before any tax is due. It comes off what is left after reliefs, and the rest is the taxable gain. The allowance is per person, so joint owners each have their own, and each enters only their own share of the figures.
4. Stacking the gain on your income
The taxable gain is added on top of your other taxable income for the year. The part of it that fits inside the unused part of your basic rate band, which is £37,700 of taxable income, is taxed at 18%. Anything above the band is taxed at 24%. So a basic-rate taxpayer with a large gain usually pays both rates, and someone whose income already fills the band pays the higher rate on all of it.
5. Reporting and paying
Capital Gains Tax on most sales of UK property has to be reported and paid within 60 days. Check on GOV.UK which date the 60 days runs from and whether your sale is one of the exceptions — this tool does not work out your deadline.
Common mistakes
Counting repairs, redecoration or replacing like for like as improvements. Only work that adds to the property counts.
Forgetting the costs of buying and selling, which reduce the gain.
Treating the whole gain as taxed at one rate. The rate depends on how much of your basic rate band your income has already used.
Entering both owners' figures when the property is owned jointly. Each owner works out their own share, with their own allowance.
Worked examples
These figures were produced by running this page's own calculator on the rates shown here, so they move when the rates do.
A basic-rate landlord selling a buy-to-let
A landlord bought a flat for £180,000, paid £3,000 in buying costs and spent £12,000 on an extension. They sell it for £260,000, paying £5,000 to sell, and have £25,000 of other taxable income.
Sale price less costs of selling
£255,000
Cost of the property (purchase, buying costs, improvements)
£195,000
Total gain
£60,000
Annual exempt amount used
£3,000
Taxable gain
£57,000
Basic rate band left after their income
£12,700
Taxed at 18%
£12,700 → £2,286
Taxed at 24%
£44,300 → £10,632
Capital Gains Tax due
£12,918
The same sale for a higher-rate taxpayer
If the same landlord's other taxable income were £60,000, their income would already fill the basic rate band, so all £57,000 of the taxable gain would be taxed at 24%: a bill of £13,680 instead of £12,918.
Figures used, and where they come from
Rates checked against their sources on 29 October 2026; due to be re-read by 27 January 2027. They are the same table the UK Property Portal members area uses.
The rates
18% within the basic rate band and 24% above it, for Disposals in the tax year 2026-27 (6 April 2026 to 5 April 2027).
Private Residence Relief, lettings relief and any other relief are not worked out. You enter the amount of gain each one removes, from your own calculation. These reliefs are complex and personal — they depend on how and when you lived in and let the property — so work them out with a qualified accountant or tax adviser.
The part of a gain that falls in each band is worked out from the taxable income you enter. Income tax is not calculated, and Gift Aid or pension contributions that widen the basic rate band, and Scottish income-tax bands, are not modelled.
Capital losses brought forward from earlier years (these can only be used down to the annual exempt amount) are not modelled; enter only losses of the same tax year, in the reliefs and losses line.
Individuals only: trustees, personal representatives, companies, non-UK residents, carried interest, Business Asset Disposal Relief and Investors' Relief are not modelled.
Gains on a property you own jointly: enter only your own share of every figure.
Whether a cost is allowable (what counts as an improvement rather than maintenance) is your call; the tool adds what you enter.
Questions
What rate of Capital Gains Tax do landlords pay?
For an individual selling residential property in the tax year 2026 to 2027, the rate is 18% on the part of the taxable gain that fits in your unused basic rate band and 24% on the rest. Which rate applies depends on your other taxable income, because the gain is added on top of it.
How much can I make before Capital Gains Tax is due?
The annual exempt amount for the tax year 2026 to 2027 is £3,000 per person. Gains up to that amount, after reliefs, are not taxed. Joint owners each have their own allowance.
Can I deduct the cost of improvements?
Yes, capital improvements that added to the property, such as an extension or a loft conversion, reduce the gain. Repairs, maintenance and redecorating do not; they are running costs. The costs of buying and selling, such as solicitors' and estate agents' fees, also reduce the gain.
When do I have to report and pay?
Capital Gains Tax on most sales of UK property has to be reported and paid within 60 days. Check on GOV.UK which date the 60 days runs from and whether your sale is one of the exceptions — this tool does not work out your deadline.
Does this work out Private Residence Relief?
No. Private Residence Relief and lettings relief depend on when you lived in the property and when you let it. Enter the amount of gain each relief removes, from your own calculation or your adviser's, and the calculator takes it off before the annual exempt amount.
An estimate worked out from the figures you enter. It is not financial or tax advice; check your own case against the guidance linked on this page, or with an adviser, before you act on it.