Fixed Ratio Position Size Calculator

How to Use the Fixed Ratio Position Size Calculator

Fixed Ratio position sizing, developed by Ryan Jones, determines how many contracts or units you should trade based on your account equity and a single parameter called delta. This calculator gives you the recommended size instantly.

1. Enter Account Balance: Your current trading equity (capital plus open/closed profit).
2. Enter Delta: The dollar amount of profit per contract you require before adding the next contract. For example, a $5,000 delta means you add one contract for every $5,000 of profit.
3. Read Recommended Contracts: The calculator shows how many contracts or units you may trade at this equity level under the fixed ratio rule.
4. Use the tier info: See how much equity is needed for the next tier so you can plan scaling.

What is Fixed Ratio Position Sizing?

Fixed Ratio is a money management method that scales position size with accumulated profit rather than with a fixed percentage of account risk. The only input is delta: the profit (per contract) required to add one more contract.

• Delta: Dollar profit per contract needed to increase size by one contract. Smaller deltas grow size faster but increase volatility of equity.
• Equity curve: Required equity for N contracts is delta × N × (N+1) / 2. So contract count grows more slowly as N increases.
• No risk %: Unlike percent-risk methods, fixed ratio does not use stop loss or risk per trade; it uses only equity and delta.

Why Fixed Ratio Matters for Traders

Fixed Ratio keeps growth tied to realized performance: you add size only after making a defined amount of profit. That can reduce over-leveraging early and smooth the path to larger size.

• Discipline: Clear rules for when to add contracts, which can reduce emotional sizing.
• Controlled growth: Position size increases in steps (delta), not linearly with account size.
• Drawdowns: After losses, your recommended contracts drop; the formula naturally reduces size when equity falls.

Fixed Ratio vs Other Position Sizing Methods

Fixed Ratio is different from fixed fractional (e.g. risk 1% per trade) or fixed ratio of risk. It ignores stop loss and risk per trade and focuses only on equity and your chosen delta. Use it when you want size to depend on accumulated profit rather than on the risk of each individual trade.

Frequently Asked Questions