Position Size Calculator

How it works

The calculator multiplies your stop loss (in points) by the contract's dollar-per-point value to get the risk per contract. It then divides your maximum dollar risk (account size × risk %) by that number to determine how many contracts you can trade while staying within your risk limit.

A fixed-fractional model like this is the standard starting point taught by every serious futures education desk, and it's the same math used internally by most prop-firm evaluation rulebooks. Typical self-directed sizing falls somewhere between 0.25% and 1% of account equity per trade; anything above 2% tends to produce drawdown sequences that most traders don't sit through comfortably, even if the system is profitable over a large sample.

Remember that points are not dollars. On ES, each point is $50 per contract. On NQ, it's $20. On GC, $100. Feeding the calculator the wrong dollar-per-point value for the contract you're actually trading is the most common sizing mistake I run into, and the one most likely to be costly rather than just uncomfortable.

This tool is for educational purposes only. Always verify position sizing with your broker before placing trades.

A worked example

Say you have a $50,000 account and cap risk at 0.5% per trade. That gives you $250 of risk to spend. You want to trade ES with an 8-point stop. ES is $50 per point, so one contract risks 8 × $50 = $400 if the stop is hit. That's already past your $250 limit, so the honest answer is zero full ES contracts on this setup.

This is exactly where micros earn their keep. MES is $5 per point, so the same 8-point stop risks 8 × $5 = $40 per contract. $250 ÷ $40 lands at 6.25, which you round down to 6 MES contracts for about $240 of risk, just under your limit. Same trade idea, same stop, sized to a number your account can actually carry.

The point isn't the specific figures. It's that a perfectly good setup can demand a position larger than your risk budget allows, and the fix is usually a smaller contract or a tighter stop, not a bigger risk percentage.

Dollar-per-point reference

These are the per-point values this calculator uses. Confirm against your broker's contract specs before trading, since they can change and micros track their full-size parent at one-tenth the multiplier.

CL and SI are quoted per point, not per tick. CL moves in $0.01 increments worth $10 each; SI moves in $0.005 increments worth $25 each. The calculator handles the tick math for you when you switch the stop unit to ticks.

Common sizing mistakes

• ✕Using the wrong dollar-per-point value. An 8-point stop is $400 on ES and $40 on MES. Mixing those up understates or overstates your risk by 10x.
• ✕Sizing off the entry instead of the stop. Your risk is set by stop distance, not by how many contracts the margin technically lets you hold.
• ✕Treating points and ticks as the same thing. On ES a point is four ticks; on CL a point is 100 ticks. Enter the unit you actually mean.
• ✕Rounding contract count up. 6.25 contracts means 6, not 7. Rounding up quietly pushes you over the risk limit you just set.
• ✕Forgetting that margin is not risk. Meeting day-trade margin on a full-size contract says nothing about whether the stop fits your account.