Position size calculator
This calculator works out how many units you can trade so that hitting your stop loses a fixed share of your capital. Enter your capital, the percentage you will risk, your entry and stop prices and the fee. It includes fees in the sum, because on a tight stop they are a large part of the risk.
Try it
Illustrative arithmetic only. Not advice. The fee is assumed to apply on both entry and exit, at the entry price. Real exits can fill worse than the stop.
How it works
The method is the standard fixed-fraction one. First it takes your capital times the risk percentage to get the money you accept losing on this trade. Then it measures how far the stop is from the entry, which is the loss per unit if the stop is hit.
A fee is paid on entry and again on exit, so the real loss per unit is the stop distance plus the round-trip fee per unit. The calculator divides the money at risk by that figure, which gives the position size in units. Multiplying by the entry price gives the position value, and dividing that by your capital gives the leverage you would need.
Because the size is set from the stop, a wider stop gives a smaller position and a tighter stop a larger one, and in both cases the amount at risk stays the same. That consistency is the whole point.
How to read the result
The headline figure is the number of units. The row below it shows the money at risk, which should equal capital times your risk percentage. If it does not, an input is wrong.
Look at leverage needed. A figure under 1x means you can hold the position outright with your own capital. Above 1x means the position is larger than your capital and you would need margin, which raises the chance of being closed out. If your sizing keeps demanding high leverage, your stop is probably very tight for your account size.
Then look at fees as a share of the risk. If the fee eats a large fraction of what you are risking, the trade is partly decided before price moves. A stop so tight that costs dominate is a common reason an apparently good setup loses money.
The example loaded above
With 1,00,000 of capital, 1% risk, an entry of 100, a stop of 98 and a 0.05% fee per side, the money at risk is 1,000 and the stop is 2 away. The round-trip fee is 0.10 per unit, so the loss per unit if stopped is 2.10. The size is 1,000 divided by 2.10, about 476 units, a position worth about 47,600, which needs 0.48x leverage and spends about 4.8% of the risk on fees. The numbers are made up, to show the method.
What this tool does not do
- It does not choose your risk percentage or your stop. Both are your decisions, and nothing here says what is sensible for you.
- It assumes you are filled at your stop price. In a gap or a fast market the real exit can be worse, so the true loss can exceed the figure shown.
- It treats the fee as a percentage at the entry price on both sides. Real fee schedules can differ by tier, order type and instrument.
- It ignores funding, margin interest and tax.
Educational only. AKQX is software only. It is not a SEBI-registered Investment Adviser or Research Analyst and gives no investment advice. This calculator does arithmetic on the numbers you enter. It does not tell you what to trade, how much to risk or whether any setup is sound. See the risk disclosure.
Questions about position size calculator
What is position sizing?
Position sizing is deciding how large each trade should be. The common method risks a fixed percentage of capital per trade, sized from the distance to the stop, so every trade risks the same amount whatever the setup.
How much of my capital should I risk per trade?
No calculator can answer that for you, and nobody should without knowing your situation. What matters is that it is a small, fixed fraction decided in advance, and that you have checked what a long losing streak at that size would do to your account.
Why does the calculator include fees?
Because on a tight stop, fees are a significant part of the risk. Leaving them out sizes the position as if trading were free, and then the real loss on a stopped trade is larger than the amount you meant to risk.
What does leverage needed mean?
It is the position value divided by your capital. Under 1x, you can hold the position with your own money. Above that, you would be borrowing or using margin, which raises the risk of liquidation.
Related
Take the number into a real test
A free account includes 10 backtests a month and 1 paper algo, so you can check a setting against history and live prices.