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Spot-trading guardrails · Not Binance official

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Position Size / Risk Calculator

Decide first how much you're willing to lose on this one trade, then work backward to how much to buy and where the stop goes. That's the risk-control mindset: control the downside instead of predicting the upside.

Suggested size for this trade
—
Max loss on this trade (at stop)—
Capital tied up—
Share of account—
How to use itA lot of people get burned by going all in with no stop. This tool flips the order: first decide what percentage of your account you're willing to lose on one trade (say 1%), then use the distance between entry and stop to work backward to how much to buy. The tighter the stop, the more you can buy on the same risk budget — but a stop that's too tight gets swept out by normal volatility. That trade-off is yours to judge.

How it's calculated

Max loss per trade = account balance × per-trade risk%; loss per coin at the stop = |entry price − stop price|; suggested quantity = max loss ÷ loss per coin. If the capital tied up comes out larger than your account (you can't buy that much in spot), the tool flags it — usually a sign your stop sits too close to entry, or your risk is set too high. Spot has no leverage; a buy spends your own money, which is very different from futures — see spot, margin and futures compared.

This is a formula to help you build a risk-control habit, not a rule that you must fill some position, and certainly not a suggestion to buy. The numbers are only a reference; the actual order is governed by the Binance app. It pairs well with the TP / SL price calculator.

Getting the most out of it

The formula: investable amount per trade = (total capital × per-trade risk%) ÷ stop distance%; quantity you can buy = investable amount ÷ current price. It sizes the position by working backward from "the most I'll lose on this trade," not from "how much I want to make."

Where it applies: this is a risk-control framework, not a return forecast. The size it gives is an upper-bound reference; the real fill, slippage and minimum order size are governed by the trading page. It keeps losses contained — it does not guarantee you won't lose.

Common mistakes: ① talking about position size with no stop set, so there's nothing to size against; ② setting per-trade risk% too high (say 20%), where a few losses in a row eat into your capital; ③ going all in and dropping risk control entirely.

Worked example: total capital 10,000, per-trade risk 2% (max loss 200), stop distance 5%: investable ≈ 4,000, and at a price of 50 that's ≈ 80 units. For why going all in with no stop is a bad idea, see the order mistakes beginners make most.