ROI Calculator
Work out the return on any investment as a percentage, a net profit or loss, and a multiple of your money. Add a time period to see the annualised return (CAGR). Works for property, shares, business investments, ad spend, and anything with a cost and a return.
Explain like I'm 5 (what even is ROI?)
You spend some money hoping to get more back. ROI tells you whether you did, and by how much. If you spent £100 and got back £150, your ROI is 50%. If you got back £80, your ROI is −20%. Simple as that.
Calculate
Enter your numbers, then press Calculate.
Results
- ROI–
- Net profit / loss–
- Multiple of money–
Annualised return (CAGR)
- Period–
- CAGR–
Recovery from current position
- Gain needed to break even–
Prove it
ROI = (Final Value − Initial Investment) ÷ Initial Investment × 100. Annualised return (CAGR) = (Final Value ÷ Initial Investment)1 ÷ years − 1, then multiplied by 100 for a percentage. Break-even gain = (Initial Investment ÷ Final Value − 1) × 100: because a percentage loss and the percentage gain needed to recover it are not symmetric (a 50% loss needs a 100% gain).
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What ROI tells you, and what it doesn't
ROI answers a simple question: for every pound I put in, how many pounds did I get back? A 50% ROI means you made 50p profit on every pound invested. A −20% ROI means you lost 20p on every pound.
It does not tell you how long it took. A 50% ROI in one year is extraordinary. The same 50% return over ten years is barely outpacing inflation. That is why the annualised return (CAGR) matters for comparing investments that ran for different lengths of time.
Annualised ROI and why it is not the total divided by years
If your investment doubled in five years, you might think that is 20% per year (100% ÷ 5). It isn't. That would only be true if the gains weren't themselves growing. In reality, each year's gain gets added to the pot, so next year's percentage applies to a bigger base. The actual annualised figure, CAGR, is 14.87% for a five-year double, not 20%.
CAGR is a smoothed number that tells you the constant annual growth rate that would take your investment from the start value to the end value. It is the fairest way to compare investments across different timeframes.
The break-even asymmetry
Losses and recoveries are not symmetric, and it trips people up. A 50% loss (£1,000 falls to £500) does not need a 50% gain to recover. It needs a 100% gain, because 50% of £500 is only £250. You need to go from £500 all the way back to £1,000, which is doubling your money. This is why protecting against large drawdowns matters more than most investors think: the maths of recovery gets progressively harder as losses deepen.
What this tool does not include
It calculates a raw return on the numbers you provide. It does not account for:
- Management fees or dealing costs
- Tax on gains (capital gains tax, income tax on dividends)
- Inflation: a 5% return during a 3% inflation year is closer to 2% in real terms
- Ongoing contributions or withdrawals during the investment period
- Risk, volatility, or probability of the return being repeated
For a fuller picture of savings and contributions growing over time, try the Compound Interest Calculator.
Nothing on this page is financial advice. For an investment decision that matters, talk to a qualified adviser who can factor in your full picture.
Related calculators
ROI on its own is a blunt instrument. These cover the specific cases it does not.
Frequently asked questions
What is the formula for ROI?
ROI % = (Final Value − Initial Investment) ÷ Initial Investment × 100. If you put in £1,000 and got back £1,500, ROI = (500 ÷ 1,000) × 100 = 50%.
What is annualised ROI (CAGR)?
CAGR is the constant annual growth rate that takes you from the initial investment to the final value. A 100% total return over 5 years is a 14.87% CAGR, not 20%, because compounding means each year grows on a larger base than the last.
What is the break-even gain?
If you're at a loss, this is the percentage gain your investment needs from its current value to recover the original amount. Losses and recoveries are not symmetric: a 50% loss needs a 100% gain to break even. The further you fall, the steeper the climb back.
Does this calculator account for fees, taxes, or inflation?
No. It calculates the return on the numbers you enter, without adjustments. Factor in fees and tax separately. For inflation-adjusted returns, use the Compound Interest Calculator with an inflation rate entered.