Binance Futures Liquidation Price Calculator (USDⓈ-M Isolated)

The formula Binance publishes

Binance’s liquidation price FAQ gives one formula covering one-way and hedge positions in both margin modes. For isolated margin, it says “TMM=0, UPNL=0” and that “WB is isolatedWalletBalance of the isolated position”. For a one-way (BOTH) position that reduces to what the calculator above implements:

LP = (WB + cum − side × Q × EP) / (Q × MMR − side × Q)

side = 1 for long, −1 for short
WB   = isolated wallet balance (initial margin + margin you added)
cum  = maintenance amount of the bracket
MMR  = maintenance margin rate of the same bracket

One warning if you compare against other sources: a widely circulated copy of the full formula has the signs of the hedge-mode terms and of cumL/cumS reversed. The formula image on Binance’s own page reads + cumL + cumS. The general method across venues is in how liquidation price is calculated.

Maintenance amount and leverage brackets

Binance’s maintenance margin is tiered by position notional:

Maintenance Margin = Position Notional × MMR − Maintenance Amount

Each bracket carries both numbers. You read yours from GET /fapi/v1/leverageBracket, which returns maintMarginRatio and cum per bracket, or from the leverage and margin page. Binance describes cum as an “Auxiliary number for quick calculation” — it is the deduction that keeps the tiered calculation continuous. That is why the calculator asks for a maintenance amount as well as a rate, and why neither is prefilled. What is maintenance margin covers the concept.

Worked example: when the bracket changes

The step most calculators skip is the one Binance spells out: if the notional at the liquidation price “falls in a different bracket”, you “must use the maintenance margin rate and the amount corresponding to the other margin levels to recalculate”.

Illustrative brackets only, not Binance’s values: bracket A covers notional up to 62,500 USDT at an MMR of 0.5% with a maintenance amount of 0; bracket B starts above it at 1.0%, with a maintenance amount of 312.5 (62,500 × 0.5%, which keeps the two continuous at the boundary). Position: 1 BTC at 60,000, 10× isolated, so WB = 6,000 USDT.

Case	Bracket used	Liquidation price	Notional there	Consistent?
Long	A	54,271.36	54,271	Yes — still in A
Short, first pass	A	65,671.64	65,672	No — that is bracket B
Short, recalculated	B	65,655.94	65,656	Yes

The long stays inside its bracket because its notional shrinks as price falls. The short’s notional grows, crosses the boundary, and the second pass moves the level about 16 USDT closer. On larger positions the gap is bigger. Check the recalculated row: at 65,655.94 the loss is 5,655.94, leaving 344.06 of margin — exactly 65,655.94 × 1.0% − 312.5.

Cross margin and hedge mode

The full formula adds TMM1 (maintenance margin of all other contracts) and UPNL1 (their unrealised PnL) in cross margin, and WB becomes the whole wallet balance. Your level then moves with every other position, which a single-position calculator cannot model.

Hedge mode changes the shape too. Binance notes that with cross margin, a long and a short on the same symbol share one liquidation price; with isolated margin they have one each. Isolated vs cross margin walks through the trade-off; hedge mode itself is covered in what is hedge mode.

Mark price triggers it

“Liquidation occurs when the Mark Price hits the liquidation price of a position.” Binance’s perpetual mark price is Median(Price 1, Price 2, Contract Price), where Price 1 adjusts the index by the last funding rate and time to the next funding, and Price 2 adds a moving average of the basis to the index. The window and index constituents change, so read them on the mark price FAQ. Live values come from GET /fapi/v1/premiumIndex (markPrice, indexPrice).

Margin ratio is maintenance margin divided by margin balance; liquidation happens at 100%.

What happens at the liquidation price

The sequence on Binance’s liquidation protocols page:

1. Smart Liquidation. The engine tries to reduce the position first, with a large IOC order, rather than closing it all at once.
2. Clearance fee. A liquidation clearance fee is charged; the insurance fund receives clearance fees from liquidations that do not go bankrupt.
3. Insurance fund. A position left with a negative balance is bankrupt and is taken over by the insurance fund at the bankruptcy price. Funds are shared by contract groups.
4. Auto-deleveraging. Only “if the Futures Insurance Funds are unable to accept a bankrupt futures position”. Opposing positions are ranked by PnL% and effective leverage and closed at the bankruptcy price, with no trading fee — see what is auto-deleveraging.

Funding is the other slow drain. Binance’s funding FAQ says it is deducted from available balance in the futures account — under cross margin, the same balance that is holding the position up. The Binance funding calculator shows how much a paying position loses per day.

FAQ

What is the maintenance amount (cum) in Binance's liquidation formula?

It is the per-bracket deduction in Binance's tiered maintenance margin: maintenance margin equals position notional times the bracket's maintenance margin rate, minus the bracket's maintenance amount. The API returns it as cum on GET /fapi/v1/leverageBracket, next to maintMarginRatio, and Binance describes it as an auxiliary number for quick calculation. Enter the cum of the same bracket as the rate you use.

Why do I have to recalculate a Binance liquidation price?

Brackets are defined by position notional, and the notional at the liquidation price is not the notional at entry. Binance's FAQ says that if the resulting notional falls in a different bracket, you must use that bracket's maintenance margin rate and maintenance amount and recalculate. A short is the usual case, because its notional grows as price rises toward liquidation.

Does this calculator work for Binance cross margin?

No, it models isolated margin in one-way mode. In Binance's full formula, cross margin adds the maintenance margin and unrealised PnL of every other contract in the account, so the level moves with positions this calculator cannot see. For cross, read the liquidation price Binance shows for the position.

Which price triggers a Binance Futures liquidation?

The mark price. Binance states that liquidation occurs when the mark price hits the liquidation price of a position. For perpetuals, mark price is the median of two index-based prices and the contract price, so it can differ from the last trade on the chart.

What happens after a Binance Futures position is liquidated?

Binance first tries to reduce the position with a large IOC order, which it calls Smart Liquidation, and charges a liquidation clearance fee. A position left with a negative balance is bankrupt and is taken over by the insurance fund at the bankruptcy price. Only if the insurance fund cannot absorb it does auto-deleveraging close opposing positions.

Related

• Liquidation price calculator (general)
• How liquidation price is calculated
• What is maintenance margin?
• What is mark price?
• What is auto-deleveraging?
• Binance Futures error -2019 (margin is insufficient)