Capital Gains Tax Calculator

Capital Gains Tax Calculator: Estimate Tax on Shares, Property & Investments

You can use our free capital gains tax calculator to find out how much tax you will have to pay on investments like stocks, real estate and other things. It has rates for 2026 in the US, UK, Australia, and Canada. There are many variations in how different countries tax gains, and rules are often changed (for example, the UK raised its rates in October 2024, and Canada shelved plans to raise the inclusion rate in 2025). This guide explains how the math works in all of them, with a full example for each.

How to Calculate Capital Gains Tax (Step by Step)

Even though the rates and benefits may be different from one country to the next, the basic four steps are the same in all of them.

1. Start with what you learned. This is how much money you got when you sold or gave away the asset.
2. Take away your cost basis. That includes the price you paid for the house in the first place, as well as any fees you paid to buy or sell it and the cost of any improvements you made.
3. So that’s your gain. You can then find your taxable gain by taking away any tax breaks, exemptions, or capital losses you can use.
4. Multiply your gain by the tax rate that applies to your country, your income, and the type of asset you own.

Core formula:

Capital Gain = Purchase Price – Allowable Costs / Sale Price Tax = Gain That Is Taxable x Rate That Applies

The hard part is almost never the math. It’s knowing exactly what an “allowable cost” is, what exemptions apply, and what rate band your gain falls into. Below, for each country, there is a full worked example that goes over each of these details.

How Is Capital Gains Tax Calculated in Each Country?

United States: Long-Term Capital Gains Tax Calculator

In the U.S., the tax on profits depends on how long you owned the asset. If you owned the assets for more than a year, you are eligible for the long-term rates of 0%, 15%, or 20%, based on your total taxable income (your gain plus your other income). If you sold the asset after holding it for one year or less, it is a short-term gain and taxed at your ordinary income rate (up to 37%).

For 2026, single filers pay 0% on long-term gains up to $49,450 in taxable income, 15% up to $545,500, and 20% above that (married filing jointly: $98,900 and $613,700). High earners may also be subject to an additional 3.8% Net Investment Income Tax (NIIT) on top of these rates once their modified adjusted gross income is above $200,000 single or $250,000 married filing jointly.

Example: A single filer with $80,000 of other taxable income sells stock held for 3 years with a $25,000 long-term gain.

Total income (income + gain) = $80,000 + $25,000 = $105,000. The $80,000 is above the 0% threshold of $49,450, so the entire $25,000 gain is in the 15% bracket ($80,000 to $105,000, both below the ceiling of $545,500). Tax on Gain = $25,000 x 15% = $3,750 MAG I of $105,000 is below the $200,000 NIIT threshold so no NIIT applies.

United Kingdom Capital Gains Tax Calculator

Since the October 2024 Budget, the UK taxes most assets, shares, funds, crypto and residential property at 18% (basic rate) or 24% (higher rate). You receive an annual exempt amount (AEA) of £3,000 each tax year. AEA is not transferrable and not used. Your taxable gain (after the AEA and any losses) then “stacks” on top of your income: the part that fits inside your remaining basic-rate band is taxed at 18%, and anything above that at 24%. This split-band calculation comes as a surprise to many as it means part of a single gain can be taxed at two different rates.

Worked example £20,000 share gain for £35,000 earner.

Less annual exempt amount: £3,000 Taxable gain: £20,000 – £3,000 = £17,000 Taxable Income after Personal Allowance (£35,000 – £12,570) = £22,430 The basic rate band remaining is £37,700 minus £22,430, which is £15,270. The first £15,270 of the gain is taxed at 18%: £15,270 × 18% = £2,748.60 CGT on the remaining £1,730 of the gain at 24% £1,730 x 24% = £415.20 Total CGT due ≈ £3,163.80

If you make a gain on the sale of UK residential property you need to tell HMRC and pay any tax due within 60 days of completion using their separate property disposal service – it is not sufficient to report it on your annual Self Assessment return.

Australia

Australia taxes your capital gain as part of your normal taxable income at your marginal tax rate. There is no separate flat CGT rate. But if you have held the asset for 12 months or more you usually qualify for the 50% CGT discount, meaning only half the gain is added to your taxable income in the first place.

Worked example: You have $70,000 of other taxable income and you realize a $40,000 gain on shares you have held for 18 months.

Discounted gain (50% CGT discount applies, held for over 12 months) = $40,000 × 50% = $20,000 New taxable income = $70,000 + $20,000 = $90,000, which is in the 30% marginal tax bracket for that portion Tax on the discounted gain = $20,000 x 30% = $6,000 (before the Medicare levy, which applies separately to total taxable income)

Note: The Federal Budget 2026-27 has proposed to replace the 50% CGT discount with a cost-base indexation approach and a minimum tax on net capital gains tax calculator from 1 July 2027. As of this update, this hasn’t come into effect, so for now the above 50% discount still stands, but it’s worth keeping an eye on if you’re planning a disposal around that date.

Capital Gains Tax Calculator for Shares & Stocks

If you sell only part of a larger position, you need a way to know which shares’ cost basis you are actually selling. In the US, FIFO (first in, first out) is the default method unless you specifically identify different shares, whereas in the UK, they use “Section 104 pooling,” which averages the cost of all your identical shares into a single pooled cost basis rather than tracking individual purchase lots.

It can also help to think of gains and dividends as separate mental buckets. A capital gain is when you sell an asset for more than you paid for it, and a dividend is income paid out by a company that you still own, and the two are generally taxed under different rules.

There are two similar-sounding anti-avoidance rules on both sides of the Atlantic. The US wash sale rule prohibits you from claiming a tax loss if you buy back a “substantially identical” security within 30 days before or after the sale. The UK’s equivalent, sometimes referred to as the “bed and breakfast” rule, similarly matches a sale against a repurchase within 30 days, which can impact your reported gain or loss if you sell and quickly rebuy the same holding.

In all four countries covered here, crypto assets are generally treated like other capital assets for tax purposes (not as currency). So buying, selling or trading crypto for profit would usually prompt the same taxable capital gains as selling shares would.

Property Capital Gains Calculator: Tax on Sale of Property

Selling your main home generally use property capital gains calculator comes with a big tax advantage, but the details differ from one country to the next. Use a capital gains tax calculator. In the US, if the ownership and use tests are met, Section 121 allows a single filer to exclude up to $250,000 of gain on a primary residence ($500,000 for married couples filing jointly). In the UK, Private Residence Relief usually gives you full exemption on your only or main home, but periods when it was let, used for business, or you own more than one property can make the calculation more complicated. Canada’s Principal Residence Exemption can fully shelter a qualifying home sale, however it still must be reported. In Australia, the main residence exemption works in a similar way for a qualifying principal home.

Second homes, rental properties and buy-to-let investments generally are not eligible for these exemptions and are taxed under the normal rules covered in the country sections above. When calculating your cost basis on any property, capital improvements (like a new roof, an addition, a kitchen remodel) can be added to your cost basis, which will reduce your taxable gain, but routine repairs and maintenance typically cannot.

Example (US Section 121): One homeowner bought their main home for $350,000. They spent $40,000 on a kitchen and bath remodel and another $30,000 in selling costs (agent commission and closing costs). They lived in the house as their main residence for the required period of time and then sold it for $600,000.

Cost basis = $350,000 (purchase) + $40,000 (improvements) + $30,000 (selling costs) $420,000 Gain = $600,000 $420,000 = $180,000 Since $180,000 is less than the $250,000 exclusion for a single filer under Section 121, the full gain is excluded. Tax due: $0 Sellers of UK residential property should be aware of the 60-day deadline for reporting and payment noted above, as this still applies whether or not Private Residence Relief subsequently reduces the bill to zero.

What Counts as Taxable Capital Gains?

Not all assets you sell will be liable to capital gains calculator Each country has some assets that are automatically exempt mainly used in the capital gains tax calculator, such as your main residence (subject to the above reliefs), personal cars in the UK, and gains inside tax-advantaged accounts such as US Roth IRAs and 401ks, UK ISAs and Canadian TFS As they are normally free of capital gains tax calculators.

In the UK gifting an asset to a spouse or civil partner is generally treated as a “no gain, no loss” transfer. In the US and Canada, it is similarly treated as a spousal rollover with tax deferred until the receiving spouse eventually sells. The treatment of inherited assets is usually different, yet again: in the US, an inherited asset is usually assigned a “stepped-up” cost basis to its value at death, which may substantially lower the taxable gain if the heir sells shortly after inheriting, but other countries have their own valuation rules relating to probate, which a local tax professional can confirm.

7 Legal Ways to Reduce Capital Gains Tax

There are a few legal ways to lower a capital gains tax bill that work in most of these countries, but the details are different:

Getting money from losses. You can balance out gains in other parts of your portfolio by selling investments that have lost value, as long as you follow wash-sale or bed-and-breakfast timing rules.

Using your yearly exemption or exclusion. The UK’s £3,000 annual exempt amount and Australia’s 50% discount over 12 months both reward clear, planned timing.

Moving money between spouses. Getting rid of (if allowed locally) Giving an asset to a spouse who is in a lower tax bracket or selling something before getting tax breaks. Put your money into a Roth IRA, an ISA, or a TFSA so that any gains are not taxed at all.

Different tax years saw different sales. If you sell things over two tax years, you can take advantage of two years’ worth of tax breaks or lower income brackets.

Putting money into retirement accounts (US): Putting money into a traditional 401(k) or IRA can lower your taxable income in the same year that you have a gain. This could help you keep more of the gain in a lower tax bracket.

Business Asset Disposal Relief (UK) gives eligible business owners and employees a lower capital gains calculator rate on the sale of certain business assets, but only for a certain amount of time.

What applies to you depends on where you live, how much money you make, and the type of asset in question, so use this as a starting point for a conversation with a tax professional instead of a do-it-yourself checklist.

Conclusion

You always do the math in the same way: proceeds minus cost basis minus exemptions and losses times the rate that applies to you. This is correct whether you file in the US, UK, Australia or Canada, and it doesn’t matter if you are selling stocks, a rental property, or your main home. It has up-to-date rates for all four countries, as well as examples and rules that are only used for properties. It also has information about shares that people often don’t understand, like cost-basis pooling and when to wash sale. You can get a rough idea of how much tax you might owe from this page and the calculator above. These are not tax tips because how much tax you owe depends on your whole financial situation and the tax laws in your country. You can use the capital gains tax calculator above to get your own number for any of the four countries it works for.

Frequently Asked Questions

Q1. How is capital gains tax calculated on shares? 

To get your gain, take the sale price and subtract your cost basis, which is the sum of the purchase price and the costs of buying and selling the item. In the US, you’ll use long-term/short-term rates, in the UK the 18%/24% split-band method, in Australia, the 50% discount then marginal rate, or in Canada the 50% inclusion then marginal rate. Then, take away any exemptions or losses you’re eligible for and apply your country’s rate.

Q2. How much capital gains tax will I pay on the sale of a property? 

It depends calculate capital gain tax on where you live, if the house is your main home, and what exemptions you may have. A qualifying main home is usually tax-free in whole or in part (Section 121 in the US, Private Residence Relief in the UK, the Principal Residence Exemption in Canada, and the main residence exemption in Australia). Second homes and rental properties are usually taxed according to the normal rules for each country, which are explained above in the section on properties.

Q3. What is the capital gains tax allowance in the UK for 2025/26? 

The UK’s annual personal allowance is £3,000 for 2025/26 (and remains at £3,000 for 2026/27), down sharply from £12,300 just a few years ago. Normally trusts get a £1,500 allowance but trusts for vulnerable beneficiaries can claim the full £3,000.

Q4. What’s the difference between short-term and long-term capital gains? 

In the US use capital gains tax calculator on sale of property, assets held for one year or less are classified as short-term and taxed at the ordinary income rates (up to 37%), while assets held for more than one year are classified as long-term and taxed at the lower 0%/15%/20% rates. Australia has a similar but different concept: assets held for 12 months or more attract a 50% discount on the taxable gain, instead of a separate rate structure.

Q5. Can capital losses reduce my capital gains tax? 

Generally yes, in all four countries, but the actual rules do vary. Generally, losses are first used to offset gains realised in the same year, and any unused loss can usually be carried forward to offset gains in future years, subject to each country’s own reporting deadlines and restrictions (e.g. the US wash-sale rule or UK bed-and-breakfast rule limiting losses on quick repurchases).

Q6. Do I pay capital gains tax on my main home? 

Usually not capital gains tax uk calculator, if your main home is truly what it is and you pass the specific tests in each country. The US Section 121 exclusion, UK Private Residence Relief, Canada’s Principal Residence Exemption and Australia’s main residence exemption can all shelter some or all of the gain but exemptions can be reduced or lost if you rented out the home for part of the time you owned it, used part of the home for business or owned more than one qualifying property at once.