Position Size Calculator
This tool answers one question: “How much should I put into this trade?” — starting from the one thing you can actually control: how much you’re willing to lose if you’re wrong.
Most traders risk 1-2% per trade — if the stop loss hits, you only lose 1-2% of your portfolio
Enter capital, risk, entry, and stop loss — results update instantly
💡 Understand it in 2 minutes
Picture it this way
Trading is like crossing a road — the smart question isn’t “what do I get if I make it” but “how badly do I get hurt if I don’t.” Traders who survive aren’t the ones who are right most often — they’re the ones who lose only a little when they’re wrong. This tool makes every loss the same small, pre-decided amount.
What each field means (in plain words)
- Total portfolio capital — all the money you have for trading. $1,000 in your exchange account? Enter 1000.
- Risk per trade— if this trade fails, what % of your total are you okay losing? Beginners use 1% (with $1,000, that’s $10 per trade) — sounds tiny, but it’s what lets you be wrong a dozen times and still have a portfolio.
- Entry price — the coin price where you plan to buy.
- Stop-loss price— the price where you admit defeat and sell. Decide it before buying, always. Think of it as: “if price reaches here, my idea was wrong — time to get out.”
A worked story
Amy has $1,000 to trade and a personal rule of risking 1% = $10 per trade. Today she wants coin A at $100, and from the chart she decides that if it drops below $90(−10%), she’ll sell.
How much should she buy? Think of it like this: if price hits her stop at $90 she loses 10% of whatever she put in. For that 10% to equal exactly $10, she should put in $100.
Check: $100 buys 1 coin → price falls from $100 to $90 → she loses $10 ✓ exactly what she planned.
Notice Amy did not go all-in with her $1,000, no matter how confident she felt — position size comes from math, not feelings.
Where beginners get confused
- “Risk 1% = invest only 1%?” — no. You can invest more than that (Amy put in 10% of her portfolio), but you only lose 1% because the stop loss cuts the trade first.
- A tighter stop lets you invest more— because each coin loses less if you’re wrong. But beware: a stop that’s too tight gets knocked out by normal price noise. Set it from the chart, not from wanting a bigger position.
- If the result says invest more than you have — your stop is very tight; the tool will warn you. The fix is to invest what you have, not to borrow or add leverage.
The formula behind it
Position size = money you’re willing to lose ÷ % distance to your stop loss — that’s it. The tool does the rest.
Frequently asked questions
›What is position sizing?
Position sizing means calculating how much money to put into a single trade based on the risk you can accept — not on confidence. It's the core of risk management that keeps portfolios alive long-term.
›How much should I risk per trade?
The widely used professional standard is 1-2% of your portfolio per trade. Ten straight losses still leaves over 80% of your capital — whereas risking 20% per trade loses more than half your portfolio in just three mistakes.
›Does risking 1% mean investing only 1% of my portfolio?
No — you can invest more (often 5-15%), but you only lose 1% because the stop loss cuts the trade first. The invested amount depends on how far your stop is from entry: the tighter the stop, the larger the position for the same risk.