Position Size Calculator
Plus stop-loss by ATR or % price move, multiple take-profit levels with R:R, breakeven win rate and exchange fees factored in. Live prices from Binance, Bybit, Kraken and OKX โ automatically.
โ๏ธ Settings
Choose which blocks to show in the calculator
๐ Form Blocks
๐ Result Blocks
๐ก Exchange for Quotes
Quotes are fetched from the selected exchange first. If not found โ tries others.
What is a position size calculator?
A position size calculator is a tool for traders that helps determine the optimal number of coins or shares to buy based on your account balance, risk tolerance, and stop-loss level. Proper position sizing is the foundation of risk management in trading.
How to use the calculator
- Balance โ enter your trading account size in dollars
- Risk โ specify the % or $ amount you're willing to risk per trade (usually 1โ2%)
- Entry Price โ your current or planned entry price
- Stop Loss โ the price level where you exit the trade at a loss
- Result โ the calculator shows the exact number of coins/shares to buy
Worked examples โ crypto and stocks
Concrete calculations on real assets. Numbers are rounded for readability.
Example 1: Bitcoin (BTC/USDT) โ long
Account balance $10,000. Risk per trade 1% ($100). Entry price $65,000. Stop-loss $63,700 (just below local support). Distance from entry to stop: $1,300, or 2% of price. Position size: $100 รท $1,300 = 0.0769 BTC. That is roughly $5,000 of notional exposure โ half the account โ but actual risk is only $100, because the stop closes the trade earlier. If your exchange requires 5x leverage minimum, use the leverage; the real risk does not change because risk is defined by the stop, not by leverage.
Example 2: Ethereum (ETH/USDT) โ short
Account balance $5,000. Risk 2% ($100). Entry $3,200. Stop-loss $3,296 (above local high, +3% from entry). Position size: $100 รท $96 = 1.04 ETH. Notional exposure $3,328. On Binance Futures with 0.06% taker fee on a market order, fees are about $2 โ roughly 2% of the risk amount. The calculator has an option to include fees in the sizing, which slightly reduces position size so net risk stays exactly $100.
Example 3: Apple (AAPL) โ classic stock trade
Account balance $25,000. Risk 1% ($250). Entry $185. Stop-loss $178 (below the 50-day moving average). Distance $7 per share. Size: $250 รท $7 = 35 shares. Notional $6,475. On Interactive Brokers with per-share commission of $0.005 (minimum $1 per order), 35 shares cost $1 in and $1 out, total $2; net risk becomes $252. The calculator has a per-share commission mode where you can set the rate, minimum, and maximum โ it then shows the exact risk including all fees.
Example 4: Tesla (TSLA) โ wide stop for a volatile stock
Account balance $50,000. Risk 0.5% ($250) โ lower bracket due to high volatility. Entry $245. Stop-loss $230 (about 2ร ATR(14) so noise does not stop you out). Distance $15. Size: $250 รท $15 = 16 shares. Notional $3,920. Notice: keeping risk at 0.5% with a wider stop means the position becomes much smaller compared to the AAPL example. That is correct behavior โ the wider the stop, the smaller the position, while dollar risk stays fixed. This is the core insight position sizing gives you.
Why does risk management matter?
Most traders lose money not because of bad entries, but because of improper position sizing. If you risk 10โ20% of your account on a single trade, even a streak of 3 losing trades can wipe out half your account. The 1โ2% rule lets you survive even a prolonged losing streak and stay in the game.
How much to risk per trade โ comparison
Risk size determines how many losing trades in a row you can survive without serious drawdown. Below: how many consecutive losses it takes to lose 50% of your account at each risk level (assuming a strategy with no edge โ 50% win rate, 1:1 risk-reward):
- 0.5% risk per trade โ you would need roughly 138 consecutive losses to lose 50% of your account. The probability of such a streak at a 50% win rate is essentially zero.
- 1% risk per trade โ 69 consecutive losses for a -50% drawdown. This is the classic level for experienced traders.
- 2% risk per trade โ 35 consecutive losses. Still safe for a trader with a confirmed positive-expectancy strategy.
- 5% risk โ 14 consecutive losses. Probability at 50% win rate is around 0.006%. Sounds safe, but in reality losing streaks of 10โ12 happen every year to any active trader. This is not insurance.
- 10% risk โ 7 consecutive losses. Probability ~0.8%. One bad week and your account is cut in half. Strongly not recommended.
Bottom line: for a beginner, 0.5โ1% is not conservatism, it is a mathematical requirement. Risk levels up to 2% should be reserved for traders with at least 100 executed trades and a proven positive-expectancy strategy.
Why this calculator is not for forex
Position sizing for crypto and stocks is straightforward math: price per unit ร number of units = position size. Forex sizing works differently โ it uses lots (1 lot = 100,000 units of base currency) and pips (price change at the fourth decimal, or second for JPY pairs). Pip value depends on the current cross-rate and the lot size, so the forex formula is: position size in lots = risk ($) รท (stop in pips ร pip value). That is separate math, which our calculator deliberately does not implement โ to avoid misleading traders with wrong calculations. For forex, we recommend dedicated calculators from Babypips, Myfxbook, or EarnForex, which have the right formulas and pip-value tables built in.
Supported exchanges
The calculator supports automatic price fetching from leading crypto exchanges: Binance, Bybit and OKX. Just enter the coin ticker โ the price loads automatically.
Exchange specifics โ Binance, Bybit, OKX
The calculator pulls live prices from three exchanges. Each has specifics worth knowing:
- Binance โ deepest liquidity on most pairs, fees 0.1% spot / 0.02% maker and 0.06% taker on futures. Minimum order size is usually $5. Use the symbol format "BTCUSDT" (no slash) in the calculator.
- Bybit โ competitive fees (0.1% spot / 0.02% maker and 0.055% taker on perpetual), with frequent fee promotions. Supports plates with better prices for limit orders. Symbol format is also "BTCUSDT".
- OKX โ low fees at higher VIP tiers, unique spot pairs, active futures market. Symbols use the "BTC-USDT" format (with a dash), but the calculator automatically converts "BTCUSDT" to the correct format when fetching prices.
The calculator itself does not place trades โ it is a sizing tool only. All actual trades you place manually on your exchange using the calculated parameters.