Trading percentage calculator
Work out the percentage change between two prices, your gain or loss, and how much you need to recover after a drawdown.
By the TradingCalculator.Pro team · Updated on · About us
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Formula
% = (End − Start) ÷ Start × 100How it works
The percentage change between two prices is the difference divided by the starting price, times one hundred. It is the simplest operation in all of trading and also the most misused, because percentages are not symmetric: losing 20% and gaining 20% does not leave you where you started.
That asymmetry is the arithmetic that governs risk management. To recover a drawdown you have to gain more than you lost, and the gap grows fast: a 10% fall needs an 11.1% recovery, a 20% fall needs 25%, a 50% fall needs 100% and an 80% fall needs 400%. It is not a mathematical curiosity: it is why position size matters more than being right.
What you get
- % change between two prices
- Trade ROI
- Recovery needed after a loss
Worked example
A $20,000 account falls to $16,000 after a bad run.
- Fall in money: 20,000 − 16,000 = $4,000.
- Percentage fall: 4,000 ÷ 20,000 × 100 = 20%.
- To get back to 20,000 you must make $4,000 on $16,000.
- Recovery needed: 4,000 ÷ 16,000 × 100 = 25%.
A 20% drawdown requires a 25% gain to get back to flat.
The figure climbs faster than intuition allows. At a 30% fall you need 42.9%; at 50%, 100%; at 70%, 233%. That is why a monthly loss limit is not pessimism: it is what keeps the recovery inside what a normal system can actually do.
How to use it
- Enter your inputs: the terms of the formula (capital, risk, prices and stop).
- The calculator applies the formula and returns the result in your instrument's units.
- Check the breakdown before trading: anything that cannot be computed is shown empty, never as zero.
Frequently asked questions
How much do you need to gain to recover a 50% drawdown?
100% — you have to double what is left. The formula is recovery = drawdown ÷ (1 − drawdown): at a 0.50 drawdown that gives 1.00, i.e. 100%. It is the arithmetic reason why limiting drawdown matters more than any entry technique.
How do you calculate the ROI of a trade?
Profit divided by the capital committed, times one hundred. Buy 300 shares at $182.40 ($54,720) and sell at $189.40, and the profit is $2,100 for a 3.84% ROI on capital committed. Measured against a whole $100,000 account, the same profit is 2.1%: both figures are true and they mean different things.
Why does a 20% gain not offset a 20% loss?
Because the second percentage applies to a smaller base. You lose 20% of 20,000 and have 16,000 left; you gain 20% of 16,000 and have 19,200, not 20,000. You are $800 short, which is exactly 20% of the $4,000 you lost.
How do I calculate the compounded return of several trades?
By multiplying the factors, not adding the percentages. Three trades of +10%, −5% and +8% do not give +13%: they give 1.10 × 0.95 × 1.08 = 1.1286, i.e. +12.86%. Over a few trades the gap is small; over two hundred, it is the difference between a projection and a fantasy.
What drawdown do eight consecutive 2% losses produce?
14.9%, not 16%. Each loss applies to the capital that remains, so the effect is 0.98 to the eighth power, which is 0.851. That same streak at 5% per trade leaves the account 33.7% down and needs 51% to get back.
How do I turn a move in pips or points into a percentage?
Divide the move by the starting price and multiply by one hundred. A move from 1.0850 to 1.0887 on EUR/USD is 37 pips, which is 0.341% of price; 8.5 S&P 500 points from 5,480 is 0.155%. It is the conversion that reveals how small the moves are that leverage turns into large results.