How to size futures positions by risk in NinjaTrader 8

Sizing by risk means deciding first how much you are willing to lose on a trade, and then letting the stop distance decide the number of contracts. Here is the formula, worked examples, and how to do it on the NinjaTrader 8 chart.

Updated: 2026-10-22

The formula

Risk is either a fixed dollar amount or a percentage of the account. Round down: rounding up means risking more than you planned.

Point values you need

These are the standard contract multipliers. Confirm them in your platform or the exchange specifications before relying on them.

Worked examples

1. Fixed dollars

Risk $200, trading ES with a 4-point stop. Loss per contract: 4 × $50 = $200. Size: 1 contract. The same trade on MES: 4 × $5 = $20 per contract, so 10 contracts.

2. Percent of account

$50,000 account, risk 1% = $500. NQ with a 25-point stop: 25 × $20 = $500 per contract, so 1 contract. On MNQ: 25 × $2 = $50 per contract, so 10 contracts.

3. Rounding down

Risk $300, ES, 4-point stop: $300 ÷ $200 = 1.5. Size: 1 contract (risk $200). Micro contracts give finer steps if you need to use more of your planned risk.

Common mistakes

• Choosing the number of contracts first and placing the stop afterwards.
• Using the wrong point value, for example mixing mini and micro contracts.
• Forgetting that commissions and slippage add to the planned loss, and that a stop can fill at a worse price.
• Changing size after a loss instead of following the same rule every trade.

How RiskReward Suite does it

On the NinjaTrader 8 chart you draw entry and stop. RRS shows the contracts from your dollar risk or percentage of the account, taking the point value from the instrument, and can apply an optional prop-style contract ceiling. One click or F1 then sends entry, stop and up to four targets together. See one-click bracket orders and the first-trade guide.

Position sizing is a risk-management tool, not advice on how much to risk. Choose an amount that fits your account and your rules.