When traders talk about liquidation, most think of leverage first: "At 10x, a 10% move gets me liquidated." That's only half true. The actual trigger for liquidation is maintenance margin — and it means your real buffer is almost always smaller than the naive math suggests.
The simple definition
Maintenance margin (MM, or MMR for the rate) is the minimum amount of collateral an exchange requires to keep a position open. If your available margin falls below this value, the position gets closed automatically — whether you want it to or not. The exchange doesn't wait for you to react; the moment your margin balance hits this threshold, a forced close begins.
Every major derivatives exchange uses some version of this mechanism. The exact percentage differs, the formula for combining it with fees differs, but the underlying idea — a floor below which the position can't survive — is universal to leveraged perpetual futures trading.
Maintenance margin vs. initial margin
The difference from initial margin (what you deposit when opening the position) is key: initial margin is always higher than maintenance margin. Your buffer to liquidation lives entirely in that gap.
Concretely: if you open a position with 10% initial margin (10x leverage) and the maintenance margin rate for your tier is 0.65%, the gap between those two numbers — roughly 9.35 percentage points — is your real cushion, not the full 10%. Fees and funding then eat into that same gap further, which is why the calculator on this site treats maintenance margin as the starting point, not the final answer.
The maintenance margin formula
On most perpetual exchanges, the maintenance margin of a position is its value multiplied by the maintenance margin rate (MMR) of the tier it falls into:
Maintenance margin = Position value × MMR
Position value is the contract size times the mark price. Tiered exchanges publish a deduction so that only the part of the position inside each tier is charged at that tier's rate: Bybit calls it the maintenance margin deduction and Binance lists it as the maintenance amount, giving Position value × MMR − Deduction. Because the mark price changes, a rising price can move a position into a higher tier.
A $375,000 position at a 0.65% rate needs $375,000 × 0.0065 = $2,437.50 of maintenance margin. With $5,000 of initial margin, $2,562.50 is left before costs, about 0.683% of the position. How to calculate liquidation price turns this into a price, and what is a margin buffer shows the same figures as a cushion.
Why it rises with position size
Most exchanges use a tiered system: the larger your position, the higher the maintenance margin rate — and the lower the maximum allowed leverage. A small BTC position might still trade at 100x or more on some exchanges; the same exchange might only allow 20x for a multi-million-dollar position, with a correspondingly higher MMR.
The reason is liquidity risk, not arbitrary punishment. Larger positions are harder for the exchange to unwind without moving the market against remaining traders. A bigger forced sale needs a bigger cushion before it's triggered, both to protect the exchange's insurance fund and to reduce the odds of the liquidation itself causing a cascade. This is also why the same nominal leverage (say, 20x) can carry very different real risk depending on how large the position is in dollar terms — a 20x position worth $5,000 and a 20x position worth $5,000,000 are not standing on the same footing at all.
A worked example
Take a real, publicly verifiable case: Binance's own BTCUSDT perpetual bracket table lists a maintenance margin rate of 0.40% for positions up to $300,000 notional, rising to 0.50% for the next tier (up to $800,000), 0.65% for the tier after that, and climbing further from there — up to 50% at the very largest, single-digit-leverage tier. That's not a hypothetical; it's the actual published structure, and it illustrates the pattern every exchange follows in some form: small tier, low MMR, high leverage cap; large tier, high MMR, low leverage cap.
At 75x leverage, the naive math gives you 1.33% of movement tolerance (1 ÷ 75). If the maintenance margin rate for your tier is 0.65%, only about 0.68% of real price movement is actually available before the trigger — roughly half of what the naive number suggested. At higher leverage the effect gets proportionally worse, because MMR tends to climb alongside position size in tiered systems, compounding the squeeze exactly when a trader can least afford it.
1 / leverage − maintenance margin rate — not simply 1 / leverage. Fees and funding then reduce that further, depending on your exchange (see the guides on funding fees and liquidation vs. bankruptcy price).How to find your exchange's actual rate
Every major exchange publishes its maintenance margin tiers publicly — usually on a page titled something like "Leverage & Margin" or "Risk Limit" under the futures trading rules section. Look specifically for the tier that matches your intended notional position value (margin × leverage), not just your margin amount, since that's what determines which row of the table applies to you.
Once you have the number, plug it directly into the calculator on this site along with your fee rate and funding rate — the tool works with any exchange's numbers, since maintenance margin rates aren't something that can be reliably auto-detected across dozens of platforms that each structure their public data differently. If you're on one of the five exchanges we track, the Binance, Bybit, OKX, KuCoin and MEXC calculators already have the fee and funding defaults filled in for you.
Common mistakes
- Checking the tier for your margin, not your notional. A $5,000 margin position at 100x leverage has a $500,000 notional value — that's the number that determines your tier, not the $5,000.
- Assuming the rate is fixed regardless of size. The MMR shown on an exchange's homepage or marketing material is usually the lowest tier's rate. Larger positions pay more.
- Ignoring fees and funding on top. Maintenance margin alone underestimates how close liquidation really is — see the related guides below for the rest of the picture.
FAQ
What is the maintenance margin formula?
Maintenance margin equals position value times the maintenance margin rate for the position's tier, minus a tier deduction on exchanges that publish one. Position value is contract size times mark price.
What is a good maintenance margin rate?
Lower is better for you as a trader — it means more price movement before liquidation. Major pairs like BTC or ETH typically start around 0.4–0.65% at the smallest position tier. Smaller-cap or lower-liquidity tokens are usually higher, sometimes 1% or more even at the smallest tier, because the exchange is pricing in the risk of not being able to close a large position cleanly.
Does maintenance margin change while my position is open?
It can. If your position size grows into a higher tier, the maintenance margin rate for that tier applies. Some exchanges also adjust rates platform-wide during extreme volatility, independent of your specific position size.
Is maintenance margin the same as initial margin?
No. Initial margin is what you deposit to open the position — always the larger number. Maintenance margin is the minimum that must remain for the position to stay open. The gap between the two is your liquidation buffer.