Position size calculator

Enter your entry, your stop and how much you are willing to lose. The calculator gives the size that loses exactly that at the stop, after the entry and exit fees.

The most you are willing to lose if the stop is hit, fees included, in your account currency.

Use the maker fee for a limit order and the taker fee for a market order. A stop usually fills as a market order.

A fixed charge per order, if your broker has one. Most crypto exchanges do not, so leave these at 0.

Position size

4.81232 units

Direction
Long, because the stop is below the entry
Position value at entry
481.23
Fees if the stop is hit
0.94

If the stop is hit you lose 25.00, fees included.

How it works

The formula

Each unit you trade can lose the distance from your entry to your stop. On top of that you pay a fee to get in and another fee to get out at the stop. Those three together are your risk per unit.

Flat fees are taken off your risk first, because you pay them whatever the size. The calculator divides what is left by the risk per unit, and that is your size.

size = (risk − flat fees) ÷ (|entry − stop| + entry × entry fee + stop × exit fee)

Worked example

Entry 100, stop 95, risking 25

You want to buy at 100 with a stop at 95 and lose no more than 25. Fees are 0.1% each way.

The distance to the stop is 5. The entry fee is 0.10 per unit and the exit fee at the stop is 0.095, so each unit risks 5.195. Then 25 ÷ 5.195 = 4.81232 units, a position worth about 481.23. If the stop is hit, fees come to about 0.94 and the total loss is 25.

Ignoring fees would give 5 units, and the same stop would cost about 25.98. On a tight stop the gap gets much bigger.

FAQ

Questions

Does this work for crypto, stocks and forex?

Yes. The size comes out in the units your price is quoted in: coins, shares or currency units. Enter the price and the risk in the same currency. If one contract covers more than one unit, divide the result by the contract size.

Why should fees be part of position size?

Because you pay them on a losing trade too. With 0.1% each way and a stop 5% away, fees add about 4% to the loss. With a stop 1% away they add about 20%, so a size worked out without fees loses noticeably more than you planned.

Where does leverage come in?

Leverage does not change the right size. It only changes how much margin the position ties up. Take the position value shown above and divide it by your leverage to see the margin.

Does it include slippage or funding?

No. A stop can fill worse than its price in a fast market, and a perpetual position pays or receives funding while it is open. If either matters for your trade, risk a little less than your limit.

Also try: Scale-in calculator

Sized it right? Now see if it paid.

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