Futures Position Size Calculator
A futures position size calculator answers one question: how many contracts can you trade so that a stop-out loses no more than the risk you planned? Enter account size, risk percentage, and stop distance — the calculator converts the stop to ticks, prices it in dollars, and floors the result to whole contracts.
The formula
Risk-based position sizing prices your stop distance in dollars, then divides it into your risk budget:
Contracts = floor( risk dollars ÷ (stop distance in ticks × tick value) )
- Risk dollars = account size × risk percentage. A $5,000 account risking 1% has a $50 budget per trade.
- Stop distance in ticks = stop distance in points ÷ tick size. An 8-point MES stop is 8 ÷ 0.25 = 32 ticks.
- Tick value is fixed per contract by the exchange — $1.25 for MES, $0.50 for MNQ. The full table is below.
The floor matters. Rounding 1.25 contracts “up to 2” doesn't trade 25% more size — it risks 60% more dollars than you budgeted. This calculator never rounds up, which also means it will tell you 0 contracts when one contract already risks more than your budget. That output is information, not an error.
Worked examples
Example 1 — MES, $5,000 account, 1% risk, 8-point stop
- Risk budget: $5,000 × 1% = $50
- Stop in ticks: 8 points ÷ 0.25 = 32 ticks
- Risk per contract: 32 × $1.25 = $40
- Contracts: floor($50 ÷ $40) = floor(1.25) = 1 contract, risking $40 of the $50 budget
Example 2 — MNQ, $2,500 account, 2% risk, 25-point stop
- Risk budget: $2,500 × 2% = $50
- Stop in ticks: 25 points ÷ 0.25 = 100 ticks
- Risk per contract: 100 × $0.50 = $50
- Contracts: floor($50 ÷ $50) = 1 contract, using the full budget exactly
Example 3 — when the answer is zero
A $1,000 account risking 1% has a $10 budget. An MNQ trade with a 50-point stop risks 200 ticks × $0.50 = $100 per contract — ten times the budget. The calculator returns 0 contracts: at that stop distance, no whole-contract position fits the plan. The honest options are a smaller-tick-value contract, a tighter stop that the trade setup actually supports, or no trade.
Tick values used by this calculator
Tick sizes and tick values are exchange-defined, set at each contract’s launch (May 2019 for the Micro E-mini equity-index contracts), and unchanged since.
| Contract | Tick size | Tick value | $ per point |
|---|---|---|---|
| MES Micro E-mini S&P 500 | 0.25 pts | $1.25 | $5.00 |
| MNQ Micro E-mini Nasdaq-100 | 0.25 pts | $0.50 | $2.00 |
| MYM Micro E-mini Dow | 1.00 pt | $0.50 | $0.50 |
| M2K Micro E-mini Russell 2000 | 0.10 pts | $0.50 | $5.00 |
| MGC Micro Gold | $0.10/oz | $1.00 | $10.00 per $1/oz |
| MCL Micro WTI Crude | $0.01/bbl | $1.00 | $100.00 per $1/bbl |
Each value has a dedicated explainer: MES, MNQ, MYM, M2K, MGC, MCL — or see the full contract spec table.
Risk percentage: what the number means
The risk percentage is the share of your account a single stopped-out trade may cost. Trading literature commonly cites figures in the 1–2% range, and the reasoning is arithmetic, not magic: at 1% risk, ten consecutive losses draw the account down roughly 9.6%; at 5% risk, the same streak costs about 40%. The right number depends on strategy, win rate, and personal tolerance — this page states the math and leaves the choice to you.
Margin is not risk
Position sizing controls risk — the dollars lost if your stop is hit. Your broker separately requires margin — a refundable performance bond held while the position is open. The two constraints are independent and you must satisfy both:
- A 2-contract MES position with an 8-point stop risks $80. At NinjaTrader's $50-per-contract intraday MES margin (Free plan, as of 11/13/2025) it also ties up $100 of margin.
- In a $150 account that margin requirement — not the risk math — is what blocks the trade.
Check the margin calculator for dated per-broker intraday margins, and the day-trading margins comparison for the full table with caveats.
FAQ
- What formula does a futures position size calculator use?
- Contracts = floor(risk dollars / (stop distance in ticks x tick value)). Risk dollars is your account size times your risk percentage. The result is always rounded down to a whole number of contracts, never up.
- Why does the calculator round down instead of rounding to the nearest contract?
- Rounding up would put more dollars at risk than the budget you set. If your risk budget is $50 and each contract risks $40 at your stop distance, two contracts would risk $80 — 60% over budget. Flooring to one contract keeps the actual risk at or below the planned risk.
- What does it mean when the calculator says 0 contracts?
- It means one contract at your stop distance already risks more than your dollar risk budget. The combination of account size, risk percentage, and stop distance does not support a single contract — the inputs have to change, not the rounding.
- Is margin the same thing as risk?
- No. Margin is a refundable performance bond your broker holds while the position is open; risk is the dollars you lose if your stop is hit. A trade can pass a risk-based sizing check and still exceed your broker's intraday margin, or vice versa. Check both before sizing a position.
- Does this position size calculator include commissions and fees?
- No. The calculation covers price risk only — stop distance times tick value. Commissions and exchange fees are additional and vary by broker; the P&L calculator on this site lets you apply dated per-side broker costs to a planned trade.
Keep the numbers straight before you size anything:
P&L calculator Margin calculator Drill the flashcardsSources
- CME Group — Micro E-mini contract specifications — tick sizes and tick values (exchange-defined at launch)
- AMP Futures — contract specifications — spec cross-verification, 2026-06-04
- NinjaTrader — futures commissions & margins — intraday margin example, rate sheet stamped 11/13/2025