Position size calculator
Decide how much of a coin to buy so that a single losing trade only costs what you choose. Enter your account, the risk you'll accept and your stop-loss — this does the math in your browser from your inputs alone.
Calculated only from the values you type — nothing is fetched or sent anywhere. Slippage and fees can make a real loss slightly larger than the figure shown.
Why position sizing is the part beginners skip
Most new traders pick a coin first and a size second — usually "how much can I afford to put in." That gets the order backwards. The size of a trade should come from how much you're willing to lose if it goes wrong, not from how much cash is sitting in the account. Position sizing is the bridge between those two numbers, and it's the single habit that keeps one bad call from doing real damage.
The mechanics are simple. First decide what you're prepared to lose on this trade — the 1–2% rule says no more than 1% or 2% of your account on any one position. On a $5,000 account that's $50 to $100. Next, look at your stop-loss: the price where you'll admit the idea was wrong and exit. The gap between your entry and your stop, per coin, is your risk per unit. Divide the dollars you'll risk by that per-unit risk and you have the exact number of units to buy. The calculator above runs that for you and also shows the full dollar size of the position, which is often larger than people expect.
Here's the part that surprises beginners: a tight stop lets you hold a bigger position for the same risk, and a wide stop forces a smaller one. The position size and the stop are linked. That's a feature, not a quirk — it means your risk stays fixed at the dollar amount you chose regardless of how volatile the coin is. A coin that swings 10% a day simply gets a smaller position than a stablecoin pair.
If you're newer to the idea of stops and leverage, our spot vs futures guide explains why the same sizing math matters even more once leverage is involved, since a leveraged loss can exceed your stop. Pair this tool with the profit and loss calculator to see the other side: what a winner is actually worth after fees.
A few rules that keep risk honest
- Set the stop before you enter, based on the chart, not on how much you'd hate to lose.
- Keep risk per trade at 1–2% so a losing streak is survivable.
- Never widen a stop to avoid being taken out — that quietly increases your risk.
- Size from the stop, not from your account balance or your conviction.
If you sign up with a referral code such as BNB968 your trading fees can be lower, which leaves slightly more of each win in your pocket — a code never makes you pay more. It has no effect on the sizing math itself; that comes only from your entry, stop and risk.