Calculator
0.06666667 units
$4,000.00 of position at entry
- Money at risk
- $100.00
- Stop distance
- $1,500.00 · 2.50%
- Position ÷ account
- 0.4x
Calculated instantly in your browser — no sign-up needed.
Educational tool, not financial advice. Results are arithmetic on the numbers you enter and say nothing about what a market will do.
How it works
Fixed-fractional sizing starts from the loss you accept if the stop is hit, not from how much you want to buy. You choose a percentage of the account to risk; the distance from entry to stop decides how many units that buys.
A stop below the entry is read as a long, a stop above as a short. Add the leverage you plan to use and the tool shows the margin the position needs — leverage changes the margin, never the size that keeps your loss to the amount you chose. Fees, slippage and gaps through the stop make the real loss slightly larger.
- Risk amount = account × risk % ÷ 100
- Units = risk amount ÷ |entry − stop|
- Position value = units × entry
- Margin needed = position value ÷ leverage
Example
A $10,000 account risks 1% on a BTC long at $60,000 with a stop at $58,500, using 5x leverage.
Risk is $100.00 and the stop is $1,500.00 away (2.50%), so the size is 0.06666667 BTC — about $4,000.00 of position, needing $800.00 of margin at 5x.
Frequently asked questions
What is a good risk percentage per trade?
Many traders risk between 0.5% and 2% of their account per trade so a run of losses does not cripple the account. It is a personal choice that depends on your strategy and tolerance — this tool simply does the arithmetic for whatever you choose.
How do I calculate position size with leverage?
Exactly the same way as without it: risk amount ÷ stop distance. Leverage only changes how much margin you post — position value ÷ leverage. Enter your leverage and the tool shows that margin, and warns if the stop sits beyond the rough liquidation distance (1 ÷ leverage), where the position would be liquidated before the stop fills.
Why is my real loss bigger than the risk amount?
Trading fees, funding on perpetuals, slippage and price gaps through the stop all add to the loss. The calculation assumes the stop fills exactly at your price.
Does it work for shorts?
Yes. Put the stop above the entry and the tool reads it as a short; the size formula is the same.
