How do I calculate position size for a Polymarket trade?

For Polymarket binary contracts (no stop-loss), use the Kelly Criterion calculator — it natively handles binary outcome sizing. For crypto spot or futures trades with a defined stop-loss, use this Position Size Calculator: enter your bankroll, risk %, entry price and stop-loss to get the exact units to buy.

What percentage of bankroll should I risk per trade?

Standard risk management: 1% conservative, 2% moderate, up to 5% maximum per single trade. Risking more than 5% on any one position exposes you to ruin risk — even a short string of losses can destroy your bankroll before you can recover.

What is the difference between position size and Kelly Criterion?

The Position Size Calculator uses a fixed risk% and stop-loss distance, suited for crypto spot/futures trades. Kelly Criterion sizes positions based on your edge and win probability — better suited for binary Polymarket contracts where there is no stop-loss.

Position Size Calculator — Risk Management for Crypto Trading

Trade Parameters

Account Balance $10,000

Risk Per Trade 1.0%

Entry Price $50,000

Stop-Loss Price $48,000

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0.0500 units

Units / coins to buy

$2,500

Dollar amount

$100

Max $ at risk

4.00%

Stop distance

0.5:1

R:R (2% target)

Buy 0.0500 units at $50,000 for a $2,500 position. Stop at $48,000 risks $100 (1.0% of account).

Position breakdown

⚡ Quick Summary

What it does: Calculates the exact number of units (and dollar value) to buy so your maximum loss equals your chosen risk% of bankroll.
Formula: Position Size = (Account × Risk%) ÷ (Entry − Stop-Loss). Risk dollars ÷ per-unit loss = units to buy.
Key rule: The 1% rule — never risk more than 1% of total account on a single trade. Even 20 consecutive full losses costs only ~18% of your account.
Bottom line: Position sizing is more important than picking trades. A poor strategy with great sizing outperforms a great strategy with reckless sizing — always.

Why Position Sizing Is the Most Underrated Skill in Trading

Most traders spend 90% of their time picking trades and 10% thinking about sizing. Professionals do the opposite. The correct position size is what separates a strategy with a slight edge from one that compounds consistently over time.

The 1% Rule Explained

The 1% rule states that you should never risk more than 1% of your total account on any single trade. With a $10,000 account, your maximum loss per trade should never exceed $100. This allows you to sustain 50+ consecutive losing trades while only losing half your capital.

Position Sizing Formula

Risk $ = Balance × (Risk% / 100) Stop distance = |Entry − Stop| Units = Risk $ / Stop distance Dollar size = Units × Entry

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Position Size Calculator

Why Position Sizing Is the Most Underrated Skill in Trading

The 1% Rule Explained

Position Sizing Formula

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