The crypto position size calculator above works out the biggest position your prop account can take on a given stop without breaking a rule. It weighs your chosen risk against any single-trade loss limit the firm sets and the daily room you have left, uses whichever is smallest, and tells you which limit decided the size. Presets cover all 27 active crypto prop firms we track.
How to use the crypto position size calculator
- Choose a firm preset. It loads any single-trade loss cap with what it is measured on, plus the daily loss limit and maximum BTC leverage.
- Enter your account size and risk per trade. We default to 0.5%; 1% is a common upper bound.
- Enter entry and stop prices.
- Set the venue leverage and your round-trip fee, for example 0.08% at Breakout and Bitfunded or about 0.11% for a non-VIP Bybit taker on both sides.
- Paste today's room from the drawdown calculator, or leave it blank to use the full daily limit.
- On a funded HyroTrader account, check the exposure caps: total margin up to 25% of the starting balance, total notional up to 2x.
- Read the notional, units, margin, loss at the stop and the binding limit.
The formula
| Step | Calculation |
|---|---|
| Risk budget | lowest of: account x risk %, single-trade cap, room left today |
| Position value | risk budget / (stop % + fees %) |
| Coins | position value / entry |
| Margin posted | position value / leverage |
Fees sit inside the denominator because a stopped-out trade loses the distance plus the round-trip cost. Leverage only changes margin, never the dollars at risk.
Worked example: ETH on a $25,000 Mubite account
Mubite caps the realized loss on any trade at 3% of equity when the trade opens and sets a 5% daily limit.
| Input | Value |
|---|---|
| Risk setting | 1% = $250 |
| Per-trade cap | 3% of $25,000 = $750 |
| Today's room | 5% = $1,250 |
| Entry / stop | $3,000 / $2,910 (3.0%) |
| Round-trip fee | 0.08% |
| Risk budget | $250 (your setting binds) |
| Notional | $250 / 0.0308 = $8,117 |
| Units | 2.71 ETH |
| Margin at 20x | $406 |
The loss at the stop uses 20% of today's room, so four straight losses still leave the account trading tomorrow. Raise the risk setting to 4% ($1,000) and the cap takes over: the budget drops to $750 and the notional to $24,351. A single loss would then use 60% of the day.
If one stop-out uses more than a quarter of today's room, the position is too big for a challenge, whatever leverage the venue offers.
Common mistakes
- Sizing from leverage. 100x on the venue does not mean 100x is safe; the stop and the room decide.
- Leaving fees out. On tight stops, a 0.11% round trip can add a third to the loss.
- Using yesterday's room. Room shrinks with each loss; refresh it from the drawdown tool.
- Forgetting the cap basis. Mubite measures on equity at entry, Dolvero on the starting balance, Fundedbit on total open risk per pair.
For which firms cap a single trade, see our stop-loss and per-trade rules guide. Leverage by firm is on the high-leverage list, and the full rules comparison lives on the rules hub.
Frequently asked questions
How do you calculate position size for a crypto prop challenge?
Find the lowest of your risk amount, any single-trade cap and the room left today, then divide it by the stop distance plus the round-trip fee as percentages.
Does higher leverage let me trade bigger?
It lets you post less margin for the same position. The size your rules allow is set by the stop distance and your loss limits, not by leverage.
Which firms limit how much one crypto trade can lose?
Mubite caps it at 3% of equity when the trade opens, Dolvero at 2% of the starting balance and Fundedbit at 2% of open risk per pair. Most others set no per-trade cap.
What risk per trade should I use in a challenge?
We default to 0.5% and treat 1% as a sensible ceiling, so several losses in a row still fit inside the daily limit.