Futures Trading Tools
Futures margin isn't one number, it's a day-trading number, an overnight number, and a maintenance number, and each one changes what "sized correctly" actually means. Six calculators that follow a single position through its full life, in the order those numbers actually come up.
A futures position gets sized once but re-checked against margin constantly: what your day-trading margin allows while the market's open, what your broker's overnight margin allows if you hold past the close, and what happens to your maintenance cushion if the trade moves against you before you decide to close it out. Most of the mistakes that catch futures traders off guard aren't sizing mistakes, they're margin-type mistakes, sizing correctly for the day session and then holding overnight without resizing for a lower overnight allowance.
The six tools below follow that exact sequence: size the trade, check it against day-trading margin, check it again against overnight margin, see what actually happens if you skip that second check, know your cushion before a margin call, and decide what to do about the contract itself as expiration approaches.
Start the same way any position gets sized: how many contracts can you trade without risking more than a set dollar amount, based on the contract's point value and your stop distance. This is your risk-based ceiling, before margin enters the picture at all.
Futures Position Size Calculator →Day-trading margin is usually a fraction of the full margin requirement, which is exactly why it can let you size bigger than you should be holding once the session ends. This tells you the actual contract count your day-trading margin allows right now.
Day-Trading Margin Calculator →Overnight margin requirements are almost always higher than day-trading margin, sometimes by a wide margin. A position sized correctly for the day session can be oversized the moment you decide to hold it past the close, and this is the number that tells you by how much.
Overnight Margin Calculator →Knowing the overnight margin number is one thing, seeing what it does to your account if you hold a day-margin-sized position overnight anyway is another. This simulator shows the real consequence of that specific mistake instead of leaving it abstract.
Day-Margin-Overnight Simulator →However the position is sized, this is the number that tells you how far the market can move against you before your account drops below the maintenance margin level and triggers a call. Knowing that distance in advance is what turns a margin call from a surprise into an expected outcome you sized for.
Maintenance Margin Cushion Calculator →Every futures contract eventually expires, and margin, liquidity, and your own thesis all factor into whether the right move is rolling to the next contract month or closing the position out entirely. This checklist walks through that decision before expiration forces it.
Contract Rollover Checklist →None of these numbers replaces the others. Sizing for risk doesn't tell you if margin allows it. Day-trading margin doesn't tell you what overnight margin allows. Overnight margin doesn't tell you your cushion before a call. And none of them tell you what to do as the contract itself approaches expiration. Run them in this order and a futures position gets checked against every constraint that actually applies to it, at the point in the trade's life where that constraint actually matters.