Capital gains tax on a property sale, with the once-in-a-lifetime home exemption.
Capital gains tax
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Chargeable gain
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Net after tax
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Why there is no flat CGT rate anymore
For years Nigeria taxed capital gains at a flat 10 percent. The 2025 tax reform, in force from 2026, changed that for individuals. A chargeable gain on a property sale no longer has its own rate. Instead it is added to your other income for the year and taxed at the personal income tax bands, so the rate you pay depends on how much other income you already have. This calculator models exactly that. It works out your gain, folds it into your other chargeable income, and charges the extra tax the bands produce. The structure is the safe thing to learn here. The specific bands are the figures the calculator applies under the reform, not numbers I am certifying, and they are administered for individuals by your state internal revenue service rather than the FIRS. The FIRS, now the Nigeria Revenue Service, sets the federal framework while the state service handles your personal assessment.
You give the tool three figures and one toggle: the sale proceeds, the combined acquisition and improvement cost, your other chargeable income for the year, and whether the property was your main home. From those it produces the chargeable gain, the tax, and what you keep.
Working out the chargeable gain
The gain is simply the sale proceeds less what the property cost you, where cost includes the original purchase price plus money spent improving it. Routine repairs do not count, but a genuine extension or upgrade that added value does, so keep the receipts. The improvement element is where careful records pay off, because every naira of allowable cost you can prove reduces the gain and therefore the tax. Once the gain is known, the tool stacks it on top of your other income and taxes only the gain at whatever bands it reaches.
Because the gain sits on top of your income, a large gain can span more than one band. That is why two people selling the same property for the same profit can owe different amounts: the one with more other income pushes the gain into higher bands. The tool captures this by taxing your income with the gain and without it, then taking the difference.
Selling a NGN 80 million property, band by band
Take the defaults: proceeds of NGN 80 million, a combined cost of NGN 50 million, and other chargeable income of NGN 12 million, on a property that is not your main home. The gain is NGN 30 million. Stacked on top of NGN 12 million of other income, it occupies the slice from NGN 12 million to NGN 42 million. The first NGN 13 million of that, taking you from NGN 12 million up to the NGN 25 million threshold, is taxed at 21 percent, and the remaining NGN 17 million up to NGN 42 million is taxed at 23 percent. Using the rates this calculator applies, the tax works out at NGN 6,640,000, leaving NGN 23,360,000 of the gain after tax.
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The home exemption, and its one catch
Tick the principal private residence box and the tool charges nothing, because the sale of your main home, together with up to one acre of grounds, is exempt. This is genuinely valuable, but there is a catch worth flagging: the relief is once in a lifetime. You cannot claim it on every home you ever sell, so use it where the gain is largest. If you own more than one property, the question of which one qualifies as your principal residence can be contested, and a home you mostly let out or used commercially may not qualify in full. A common mistake is to assume any house you live in is automatically exempt regardless of how often you have claimed before. Because the rules are detailed and changing under the reform, confirm your eligibility and the current treatment with your state internal revenue service before you rely on the exemption.
Can I deduct estate-agent fees and legal costs from the gain?
This calculator only nets your acquisition and improvement costs against the proceeds, so it does not add selling costs separately. In practice, allowable incidental costs of buying and selling can affect the chargeable gain, but the rules on what qualifies are detailed. Keep records of agent and legal fees and ask your state internal revenue service how they are treated for your sale.
What if I reinvest the proceeds in another property?
For property there is no automatic roll-over in this tool, and the gain is taxed in the year of sale regardless of what you do with the money. Some reinvestment reliefs exist elsewhere in the law, notably around shares, but do not assume one applies to a house. Check the current position with the FIRS framework and your state revenue service before counting on any deferral.