Every perpetual futures contract carries a small periodic payment passed between its long and short traders. That payment is the funding rate, and it is the single mechanism that keeps a perp's price anchored to the spot index it is supposed to track. If you hold a perp for more than a few hours, the funding rate quietly decides how much your position costs — or how much it pays — and most traders have never actually computed the number for their own position.
This article breaks the rate down completely: what it is and why perpetuals need it, the exact payment formula with a worked example on a $10,000 position, how to read the sign (positive versus negative), how to turn an 8-hour rate into a comparable annual figure, how to use the Funding Rate Calculator on this site, and what funding rate arbitrage really involves — including the risks that make it less than risk-free.
What funding rate actually is
A perpetual futures contract ("perp") has no expiry date, so it never converges to the spot price the way a quarterly future does at settlement. Without a forcing mechanism, a perp could drift far from the index it tracks. The funding rate is that mechanism: at regular settlement times, one side of the market pays the other, and the size of the payment is driven by how far the perp's price is from the spot index. If the perp trades rich (above the index), longs pay shorts; if it trades cheap, shorts pay longs. The result is a small but constant pressure that pulls the two prices back together.
Two things are worth being precise about. First, funding is paid between traders, not to the exchange: it is a transfer from the long side's wallets to the short side's wallets (or vice versa), credited and debited at each settlement. Second, most major venues settle every 8 hours — typically 00:00, 08:00 and 16:00 UTC — and quote a neutral baseline of 0.01% per period, but the settlement interval varies by contract: some altcoin perps settle every 1 hour or every 4 hours, and the displayed rate is always per stated period, never per day.
The funding rate formula
Once you know the sign convention, the payment for a holding period is straightforward: Payment = position notional × funding rate × (hours held / 8) × sign
The sign is the part people get wrong. The convention: a positive funding rate means longs pay. A long position at a positive rate therefore has a negative cash flow, and a short position at the same rate has a positive one. A negative rate inverts everything: shorts pay, longs receive. Two signs — the rate's and your position's — decide who pays, and mixing them up is the single most common funding mistake.
Equally important: funding is charged on the position's notional value (in quote currency), not on the collateral you posted. A $10,000 position at 10x leverage has only $1,000 of margin behind it, yet funding is calculated on the full $10,000. Leverage does not shrink your funding bill — it multiplies everything, including your liquidation risk.
Worked example
Take a $10,000 position on a market where funding sits at the baseline 0.01% per 8 hours:
- Long at +0.01%: pays $1.00 per settlement — $3.00 per day (3 settlements), $21.00 per week, $90.00 per month (90 settlements).
- Short at +0.01%: receives the same amounts.
- Short at -0.03%: pays $9.00 over a day on the same $10,000.
Now raise the rate to 0.1% — ten times baseline, but a routine level on a hot market:
- Long at +0.1%: pays $10.00 per 8 hours, $30.00 per day, $210.00 per week, $900.00 per month.
- Short at +0.1%: receives $210.00 per week instead of paying.
Finally, simple versus compounded. Most traders see funding as simple interest, and for short holds it is: each settlement bills rate × notional at a fixed period. But if you hold for a month and each amount is added to (or deducted from) your effective position value, the effect compounds. At 0.1% over 90 settlements on $10,000, the simple calculation gives $900.00 and the compounded one gives $941.25 — $41.25 more, about 4.6%. At baseline rates the difference is cents; at persistently elevated rates it is real money, in both directions.
What positive and negative funding actually tell you
Funding reads best as a crowdedness gauge, not a price signal. Persistent positive funding means the long side is paying to keep its exposure — the market leans bullish, and the more euphoric it gets, the higher the rate climbs. Persistent negative funding is the mirror image: shorts pay, the crowd sits on the other side of the book, and it is fear (or short positioning) that is being priced.
Extreme values are a sentiment input, not a trigger. A rate at several times baseline tells you the long side is crowded and expensive; a crowded, over-leveraged long side is also the fuel for liquidation cascades, so an elevated rate is worth checking against where leveraged positions sit — exactly what the Crypto Liquidation Calculator computes. In a strong trend the rate can stay elevated for weeks, so treat it as one context input beside price and open interest — not as a standalone reason to flip a position.
How to read and annualize a funding rate
The quoted rate is per 8-hour period (on most venues), so the standard conversion to an annual figure is rate × 3 × 365:
- 0.01% (baseline) → 10.95% annualized.
- 0.05% (five times baseline) → 54.75% annualized.
- 0.10% → 109.5% annualized.
Three caveats keep the annualization honest. First, the displayed rate is a snapshot — it is recomputed at every settlement and can flip sign within hours, so "109.5% annualized" is what would happen if the current rate persisted, not an expected return. Second, annualizing only works when comparing rates with the same settlement interval; a contract settling hourly and one settling every 8 hours are not comparable in raw percentages. Third, at a negative rate the same calculation tells you what it costs the short side — your position's sign decides whether the number is income or expense.
Using the funding rate calculator
The funding rate calculator on this site takes five inputs: position size (in quote currency), direction (long or short), the current funding rate as a percentage, the number of hours you expect to hold, and whether settlements are treated as simple or compounded. It returns the total funding payment for your period, the annualized rate, summary cards for 8 hours, 24 hours, one week and one month, and an hour-by-hour table of every settlement with a running cumulative — capped at a month of rows, with the summary cards covering anything longer.
The workflow is short: read the live rate and the next settlement time on your exchange, enter your actual position size, and check that the holding cost is small relative to your reason for holding. Two habits make the number useful rather than decorative. First, decide the position from your risk budget before projecting its carrying cost — the position sizing calculator and the Position Size Calculator size a position from a fixed risk amount and a stop, so the funding bill becomes a by-product of a risk you already decided, not a surprise. Second, keep the holding period realistic: funding is a rate × time cost, so a trade you plan to hold one day costs one-twentieth of the same trade held a month.
One more use for the same numbers: sanity-checking whether the carry is worth entering at all. If your expected edge on the trade is smaller than the funding you would pay over the expected holding time, the trade is negative before a tick moves — the Risk/Reward Calculator puts that comparison on one screen.
Funding rate arbitrage and its real risks
When funding stays positive, there is a classic strategy built on it: buy the asset in spot and short the same notional in the perpetual. The two legs cancel most of the directional exposure, and while funding is positive you collect the payment the long side would otherwise make — the "cash and carry". Its return is the funding stream minus entry and exit costs, and on markets where funding runs well above baseline it can be substantial over weeks.
It is not risk-free, and the risks are specific. The short leg of the perpetual can be liquidated by a sharp rally — it has a margin requirement and a liquidation price like any short, so size it with the liquidation price calculator before committing. Funding can flip negative, at which point the carry works against you. Entry and exit fees plus slippage shave the harvest on every rebalance. And if the legs drift apart, you are no longer collecting carry — you are running a directional bet with extra steps. A useful honest check: the short leg's size is a sizing decision first and an arbitrage decision second — exactly the work of the position sizing guide.
Worth knowing as neighbors: expiring futures express the same long-term carry as a fixed basis instead of a fluctuating funding stream, if you want the exposure without the settlement-to-settlement variation (Futures Contract Calculator). And the discipline that keeps a carry alive in a hot, crowded market is knowing exactly where your leveraged leg stops existing — the liquidation price guide walks through that arithmetic end to end.