Crypto Position Size Calculator: Risk-Based Sizing for Longs & Shorts

What this calculator actually does

Every blown-up trading account I’ve ever heard the story of died the same way: position size chosen by feeling, stop-loss chosen by hope.

This tool reverses the order. You decide what the trade is allowed to cost you first (a percentage of your account), you place the stop where your idea is actually wrong, and the calculator tells you the only position size consistent with both.

The math is fifth-grade stuff. Entry minus stop gives risk per unit. Your risk budget divided by that gives units. And that simple division is the difference between traders who survive losing streaks and traders who post loss porn.

The numbers worth staring at

Implied leverage tells you whether the position even fits your account. If the tool warns that a setup needs 5x to work, the honest reading is that your stop is too tight for your risk appetite. Not that you need more leverage.

Reward-to-risk (add a target price to see it) tells you whether the trade is worth taking at all. Below 1.5 to 1, you need to be right more often than most people are.

Stop distance shows how far the market has to move against you before you’re out. In crypto, size that with respect: 2% wicks happen while you sleep.

What it can’t do

It can’t make the stop honest. The math assumes your stop fills at its price, and real fills come with slippage, especially in fast moves on thin pairs.

It also can’t stop you from moving the stop once you’re in the trade, which is where sizing discipline usually goes to die.

My personal rule, take it or leave it: the risk percentage gets decided on a calm day, once, and never renegotiated mid-trade. One percent means one percent on the boring trades and on the “this one is different” trades, because the account can’t tell the difference.

If you’re building your first habits, this pairs naturally with the DCA calculator: one tool for investing without timing, one for trading without hoping. And whichever exchange you trade on, make sure it passed the red-flag checks first. Position sizing can’t protect funds a platform won’t give back.

FAQ

What percentage of my account should I risk per trade?

The widely used range among disciplined traders is 0.5% to 2% per trade, with 1% as the common default. The logic is survival math: at 1% risk, a brutal streak of ten straight losses costs about 9.6% of the account. At 10% risk, the same streak costs 65%. You size for the losing streak, because sooner or later you’ll meet one.

Does this work for short positions?

Yes. Enter your short entry and place the stop-loss above it; the calculator detects the direction automatically and marks the result as a short. The math is symmetric: risk per unit is the distance between entry and stop, whichever side it’s on.

Why does the calculator warn me about leverage?

Because a position larger than your account requires margin, and margin adds risks the sizing math doesn’t cover: liquidation prices that can sit uncomfortably close to a tight stop, funding costs, and forced closure during wicks. The warning triggers so you can choose between widening the stop with a smaller position or accepting the leverage knowingly.

What’s a good reward-to-risk ratio?

Most traders look for at least 1.5:1 to 2:1, meaning the target pays at least one and a half to two times what the stop costs. The reason is arithmetic, not tradition: at 2:1 you stay profitable winning only 40% of the time, while at 1:1 you need to beat a coin flip after fees, and after fees is where most edges quietly disappear.