Stock Trading Profit Calculator
Calculate your real share trading profit or loss after broker fees, Stamp Duty, and Capital Gains Tax. See your break-even price, return on investment, and compare ISA vs taxable account results — updated for 2026/27 UK CGT rates.
Know Your Real Trading Profit
The price difference between buy and sell is only part of the story. Broker commissions, Stamp Duty Reserve Tax, and Capital Gains Tax all eat into your returns. This calculator shows you exactly what you keep after every cost is accounted for.
Calculate Your Stock Trading Profit
Your Trade Results
Net Profit After All Costs
£0
0% ROI 0% annualisedCost Breakdown
- Total Purchase Cost:£0
- Total Sale Proceeds:£0
- Buy Commission:-£0
- Sell Commission:-£0
- Stamp Duty (0.5%):-£0
- Total Fees:-£0
- Gross Profit (before CGT):0
Trade Summary
- Price Change:£0 (0%)
- Break-Even Sell Price:£0/share
- Cost per Share (all-in):£
- Total Invested:£0
- ROI:0%
- Annualised Return:0%
Capital Gains Tax Estimate
- Gross Gain on This Trade:£0
- Other Gains This Year:£0
- Losses Offset:-£0
- Total Gains:£0
- Annual Exempt Amount:-£3,000
- Taxable Gain:£0
- CGT Rate Applied:18%
- CGT Due:£0
Net Profit After CGT
£0
About This Calculation
This calculator provides estimates based on 2026/27 CGT rates and current SDRT rules. Your actual tax position depends on your complete financial circumstances, including all capital gains and losses across all assets in the tax year. HMRC's share matching rules (same-day, 30-day, and Section 104 pool) may affect your cost basis for CGT purposes. For complex portfolios, consider using specialist CGT software or consulting a qualified financial adviser. For official CGT guidance, see GOV.UK Capital Gains Tax.
How Stock Trading Costs Work in the UK
When you buy and sell shares in the UK, several costs reduce your actual profit. Understanding each one ensures you know exactly what you keep from every trade.
Broker Fees
Broker commissions vary widely in the UK. Traditional platforms like Hargreaves Lansdown and AJ Bell charge £5 to £12 per trade. Commission-free platforms like Trading 212 and Freetrade charge nothing per trade but may have other fees. Each trade typically involves two commissions — one when you buy and one when you sell.
Platform fees (annual custody charges) are separate and not included in this calculator, but can significantly affect long-term returns on larger portfolios.
Stamp Duty (SDRT)
Stamp Duty Reserve Tax (SDRT) of 0.5% is charged on electronic purchases of UK-listed shares. It's automatically deducted by your broker at the point of purchase. You do not pay SDRT when selling shares.
SDRT applies even to purchases inside ISAs and SIPPs. However, most overseas-listed ETFs (including many popular index trackers listed on European exchanges) are exempt from SDRT, making them more cost-effective for regular investors.
Capital Gains Tax
If you hold shares outside an ISA or pension and sell at a profit, you may owe CGT. For 2026/27, the annual exempt amount is £3,000. Gains above this are taxed at 18% (basic rate) or 24% (higher rate). The rate depends on your total taxable income plus the gain.
Shares held in a Stocks and Shares ISA or pension (SIPP) are completely exempt from CGT, making tax-sheltered accounts essential for serious investors.
2026/27 Capital Gains Tax Rates at a Glance
| Detail | 2026/27 |
|---|---|
| Annual Exempt Amount | £3,000 |
| Basic Rate (within basic band) | 18% |
| Higher Rate (above basic band) | 24% |
| Business Asset Disposal Relief | 18% (£1M lifetime) |
| Investors' Relief | 10% (£10M lifetime) |
Tax-Free Accounts
| Account | CGT | Dividend Tax | Annual Limit |
|---|---|---|---|
| Stocks & Shares ISA | Exempt | Exempt | £20,000 |
| SIPP / Pension | Exempt | Exempt | £60,000 (AA) |
| General Account | 18% / 24% | 8.75% / 33.75% | No limit |
Tax-Efficient Investing Strategies
Use Your ISA Allowance First
The £20,000 annual ISA allowance is the single most important tax shelter for UK investors. All gains and dividends inside an ISA are completely tax-free, with no reporting required. If you're not using your full allowance each year, you're potentially paying tax unnecessarily. Consider a Stocks & Shares ISA for long-term investments alongside your cash savings.
Bed and ISA
Sell shares held in a taxable account and immediately repurchase them inside your ISA. This crystallises any gain (use your £3,000 annual exempt amount) and shelters future growth from CGT and dividend tax permanently. Most UK brokers offer this as an automated process. Over years of compounding, the tax savings can be substantial.
Harvest Losses
If you hold shares at a loss, consider selling them before the end of the tax year to crystallise the loss. Capital losses can be offset against gains in the same year or carried forward indefinitely. This is particularly valuable if you have other gains exceeding your £3,000 annual exempt amount. Report losses to HMRC within four years to preserve carry-forward rights.
Use Both Spouses' Allowances
Transfers between spouses and civil partners are CGT-free. By transferring assets to a lower-earning spouse before selling, you can use both partners' £3,000 annual exempt amounts (£6,000 total) and potentially have gains taxed at 18% instead of 24%. This is one of the simplest and most effective CGT planning strategies available.
Pension Contributions from Gains
If you realise a large capital gain, consider using some of the proceeds to make a pension contribution. Pension contributions attract tax relief at your marginal rate (20%, 40%, or 45%), effectively reducing your overall tax burden for the year. Use our Pension Tax Relief Calculator to see how much relief you'd receive, or explore salary sacrifice for additional NI savings.
Spread Sales Across Tax Years
If you're sitting on a large unrealised gain, consider selling in stages across multiple tax years. Each year gives you a fresh £3,000 annual exempt amount. Selling £3,000 of gains each April can shelter significant growth over time. Combine this with the bed and ISA strategy for maximum tax efficiency.
Frequently Asked Questions
Stock trading profit is the sell price minus the buy price, multiplied by the number of shares, minus all costs. Costs include buy commission, sell commission, and Stamp Duty Reserve Tax (0.5% of purchase value for UK shares). The formula is: Profit = (Sell Price x Shares) - (Buy Price x Shares) - Buy Commission - Sell Commission - Stamp Duty.
Your real return also depends on Capital Gains Tax if you hold shares outside an ISA or pension. For a comprehensive view of your overall financial position, consider your share investments alongside your private pension and savings goals.
Stamp Duty Reserve Tax (SDRT) is a 0.5% tax charged on electronic purchases of UK-listed shares. It is automatically collected by your broker at the point of purchase. You do not pay SDRT when selling shares, buying most overseas-listed ETFs, or purchasing shares in AIM-listed companies (since 2014, AIM shares have been exempt).
SDRT applies even to purchases inside ISAs and SIPPs. For a £10,000 share purchase, SDRT costs £50. On a £50,000 purchase, it's £250. This is a meaningful cost for frequent traders or large positions.
For 2026/27, the CGT annual exempt amount is £3,000. Gains above this are taxed at 18% if your total taxable income plus the gain falls within the basic rate band (up to £50,270), or 24% on gains above the basic rate band. From 6 April 2026, all assets — shares, property, and crypto — are taxed at the same rates.
Shares held inside an ISA or pension (SIPP) are completely exempt from CGT. Losses on share sales can be offset against gains in the same tax year or carried forward indefinitely if reported to HMRC within four years. For detailed CGT guidance, see GOV.UK Capital Gains Tax.
No. Shares held inside a Stocks and Shares ISA are completely exempt from both Capital Gains Tax and dividend tax, regardless of how large the gain. The ISA allowance for 2026/27 is £20,000 per tax year. You still pay Stamp Duty (0.5%) on UK share purchases inside an ISA, but all gains and dividends are tax-free forever.
This makes ISAs one of the most tax-efficient ways to invest. Over a 20-year period, the compounding benefit of tax-free growth can be worth tens of thousands of pounds compared to a taxable account. For long-term retirement planning alongside ISA investing, explore our Workplace Pension Calculator and Retirement Age Calculator.
The break-even price is the minimum price per share you need to sell at to recover your total investment including all fees. It's calculated as: (Buy Price x Shares + Buy Commission + Stamp Duty + Sell Commission) / Number of Shares. This tells you the exact point where your trade moves from loss to profit.
For example, buying 100 shares at £10 each with £10 buy/sell commissions and 0.5% stamp duty: Total cost = £1,000 + £5 (SDRT) + £10 (buy) + £10 (sell) = £1,025. Break-even price = £1,025 / 100 = £10.25 per share.
Yes. Capital losses from share sales can be offset against capital gains in the same tax year, reducing your CGT liability. If your total losses exceed gains, unused losses can be carried forward indefinitely. You must report losses to HMRC within four years via Self Assessment to carry them forward.
Note: the 30-day "bed and breakfast" rule prevents you from selling shares at a loss and repurchasing the same shares within 30 days. If you do, the loss is not allowed for CGT purposes. However, you can repurchase inside an ISA (bed and ISA) or buy a similar but different fund to maintain your exposure.
Bed and ISA is a strategy where you sell shares held in a taxable general account and immediately repurchase them inside your ISA. This crystallises any gain (using your £3,000 annual exempt amount if applicable) and shelters all future growth from CGT and dividend tax permanently.
Most UK brokers (including Hargreaves Lansdown, AJ Bell, and interactive investor) offer bed and ISA as an automated process. It's one of the most effective long-term tax planning strategies for UK investors who have accumulated shares outside their ISA. For broader tax planning, explore our HMRC Pension Tax Calculator and Tax Relief Calculator.
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Disclaimer
This calculator provides estimates only and does not constitute financial or tax advice. Capital Gains Tax calculations are simplified and do not account for HMRC's share matching rules (same-day, 30-day bed and breakfast, Section 104 pooling), which may affect your cost basis. Your actual CGT liability depends on your complete financial circumstances, including all capital gains and losses across all asset classes in the tax year. For complex portfolios, use specialist CGT software or consult a qualified financial adviser. Sources: HMRC Capital Gains Tax, HMRC Tax on Shares, GOV.UK ISA, MoneyHelper Investing, FCA Consumer Hub.