Compare MES vs ES futures at the same dollar risk. This micro e-mini position size calculator shows contracts, actual risk and commission for any stop loss.
The MES vs ES Position Size Calculator works with any trading approach. Whether you place stops using price action, moving averages, volatility bands or a system you built yourself, the position sizing mathematics are identical. The only question is whether the contract you trade lets you honour both your stop and your risk limit.
The E-mini S&P 500 (ES) moves $50 per index point. The Micro E-mini (MES) tracks the same index at $5 per point — one tenth of the size. On a $50,000 account risking 1% per trade, that $500 buys you a single ES contract with a stop no wider than 10 points. If your analysis says the stop belongs 20 points away, ES simply doesn't fit: you either take on double the risk or move the stop somewhere the market never told you to put it.
MES removes that trade-off. The same $500 covers five MES contracts at a 20-point stop, or two at 50 points. Your dollar risk stays fixed while the stop goes wherever your method says it should — and you gain finer control over size, including the option to scale out a piece at a time.
Enter your account size and risk, then move the stop slider to see how many contracts of each you can hold, what you actually risk, and what it costs in commission.
All-in cost per contract, per side. Rates vary by broker and plan — enter your own to see the real difference.
| Stop | Ticks | ES contracts | ES risk | MES contracts | MES risk | Fits with |
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Contracts are rounded down, so actual risk never exceeds your limit.
A casino doesn't know whether the next hand of blackjack will win or lose, and it doesn't need to. It knows its edge is small, positive and repeatable, and it sizes every table limit so that no single hand can hurt it. Over thousands of hands, the mathematics does the rest. Trading works the same way. It doesn't matter which methodology you use to find your entries — what determines long-term profitability is how much you risk per trade, how you manage winners, and whether your edge has positive expectancy over a large sample of trades.
That is why the stop and the position size have to be decided together. Your stop is where your trade idea is proven wrong. Your risk per trade is how much you are willing to lose when that happens. Divide one by the other and you get the position size:
contracts = risk in dollars ÷ (stop in points × point value)
With ES, the point value is large enough that the division often comes out below one. When it does, traders tend to do one of two things: tighten the stop until one contract fits, or keep the stop and accept more risk than planned. The first puts the stop inside normal market noise, so good ideas get stopped out before they have a chance to work. The second quietly breaks the risk rule that keeps an account alive through a losing streak. Neither is a trading-method problem. Both are contract-size problems.
Thinking in terms of risk also changes how you measure results. If every trade risks the same amount — call it 1R — then a trade that makes three times what it risked is a +3R winner, and a stopped-out trade is −1R, whatever the stop size in points. Consistent R is what lets you judge your edge over a large sample, and it only stays consistent when the contract is small enough to size precisely at any stop.
MES makes that precision possible. At ten times the granularity, you can hold the same risk across a wide range of stop sizes, so a 12-point intraday stop and a 60-point swing stop can carry the same 1R. Commission is higher per point of exposure, because you pay per contract, but at typical rates the difference is a few dollars per round trip — small next to the cost of a stop in the wrong place. Use the commission settings above to check it against your own broker.
For larger accounts the logic runs the other way: once your risk per trade comfortably covers several ES contracts at your usual stop, ES and MES carry the same exposure and ES costs less to trade. The calculator shows where that crossover sits for your numbers.