By Katie
· Free tool · Reviewed October 1, 2026
Position size is how much you buy or sell on a trade. It should come from the money you are willing to lose, not from how sure you feel. Enter your numbers and the calculator gives you the size in lots, units or shares.
Your position size
0.20 lots
Contents (11)
How to use the position size calculator
- Choose the market: forex, or stocks, gold and crypto.
- Enter your account balance and the percentage you are willing to lose on this trade.
- Enter your stop: in pips for forex, as a price for everything else.
- For forex, pick the currency pair. For pairs that start with USD, also enter the current price.
- Read the size. If your platform needs whole steps, round down, never up.
What is position size?
Position size is how much you buy or sell on one trade: how many lots in forex, how many shares in stocks. It is the one number in a trade that you control completely. The market decides where the price goes. You decide how much that move costs you.
That is why the size should never come from a feeling. It comes from two things you decide before the trade: how much you are willing to lose, and where your stop goes.
The position size formula
position size = money at risk ÷ (stop distance × value of that distance)
Money at risk is your balance times your risk percentage. In forex, the stop distance is in pips and its value is the pip value per lot. For stocks the formula becomes simply: money at risk ÷ (entry − stop).
Example: forex
You have 5,000 dollars and risk 1%, so you can lose 50 dollars. You buy EUR/USD with a 25-pip stop. On EUR/USD a pip is worth 10 dollars on a standard lot.
50 ÷ (25 × 10) = 0.20 lots. That is 20,000 units, 2 mini lots or 20 micro lots. If the stop is hit, you lose 25 pips × 2 dollars a pip = 50 dollars, exactly what you planned.
Example: stocks
Same account, same 50 dollars of risk. You buy a stock at 40.00 with a stop at 38.50, so each share risks 1.50.
50 ÷ 1.50 = 33.3, so you buy 33 shares. The position is worth 1,320 dollars, and if the stop is hit you lose about 49.50 dollars.
Pip values for common pairs
| Pair | Pip value per standard lot |
|---|---|
| EUR/USD, GBP/USD, AUD/USD, NZD/USD | $10 |
| USD/JPY at 150.00 | about $6.67 |
| USD/CHF at 0.8800 | about $11.36 |
| USD/CAD at 1.3700 | about $7.30 |
For pairs that start with USD, the pip value changes with the price, which is why the calculator asks for it. For other pairs, such as EUR/GBP, take the pip value from your trading platform and choose “Other pair”.
How much should you risk per trade?
Many traders risk 1% of the account or less on a single trade. It sounds small, but it is what keeps a losing streak survivable. Every strategy has losing streaks. The table shows what ten losses in a row do to the account at different risk levels.
| Risk per trade | After 10 losses in a row |
|---|---|
| 0.5% | −4.9% |
| 1% | −9.6% |
| 2% | −18.3% |
| 5% | −40.1% |
Common mistakes
- Choosing the size first and the stop afterwards. The stop goes where the trade idea is wrong. The size follows from it.
- Moving the stop closer to trade bigger. A tight stop gets hit by normal market noise more often.
- Rounding up. If the calculator says 0.137 lots, trade 0.13, not 0.14.
- Forgetting the spread. On short timeframes it adds to the real distance to your stop.
- Risking more after a loss. The size should be the same after a win and after a loss.
Frequently asked questions
How do you calculate position size in forex?
Multiply your balance by your risk percentage, then divide by your stop in pips times the pip value per lot. With 5,000 dollars and 1% risk you can lose 50 dollars, and 50 ÷ (25 pips × 10 dollars) = 0.20 lots.
What is a lot in forex?
A standard lot is 100,000 units of the first currency in the pair. A mini lot is 10,000 units and a micro lot is 1,000. Most platforms let you trade in steps of 0.01 lots.
How much should I risk per trade?
Many traders risk 1% of the account or less. Ten losses in a row at 1% cost less than 10% of the account. At 5% per trade, the same ten losses cost about 40%.
Does leverage change my position size?
No. Leverage only decides how much money the broker holds as margin. Your size should come from your risk and your stop.
What if the size is smaller than my broker allows?
Then the trade is too big for your account with that stop. Skip it, or wait for a setup with a closer logical stop. Do not raise the size.
Can I use it for gold or crypto?
Yes. Choose the stocks, gold or crypto setting, enter the entry and stop as prices, and the result is in units, for example ounces or coins. Check how many units one lot is on your platform.
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- Lot Size Calculator
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- Gold Lot Size Calculator
- Risk/Reward Ratio Calculator
- Profit Calculator
- Stock Average Calculator
- Trading Expectancy Calculator
- Break-Even Win Rate Calculator
- All trading tools
Learn it properly
- 1How to Manage Risk in TradingThe two decisions and one division behind every position size.
- 2How Much Money Do You Need to Start Trading?Why a very small account struggles to size trades properly.
- 3How to Stop Revenge TradingWhat happens when the size comes from emotion instead of a rule.
For education only, not financial advice. Trading carries a real risk of losing money. Nothing you enter is saved or sent anywhere: the calculator runs in your browser.