Funding rate calculator
Enter your position size, the funding rate and how many days you will keep it open, and I will tell you how much funding you pay or receive and what share of your margin it takes. It is the calculation from the guide funding rate: what it is in perpetual futures.
Total funding-90 USDT
At each payment-1 USDT
Per day-3 USDT
On your margin-9%
With the rate at 0.01% every 8 h, over 30 days you pay 90 USDT: 9% of your 1,000 USDT margin, if the rate stays the same.
With the current rate the whole time. Check the rate and the time of the next payment on your exchange: they change every period.
What it costs to hold a position for a month
A 10,000 USDT long, with 1,000 of margin at x10 and payments every 8 hours. With a positive rate, this is what you pay; with the same rate negative, you would receive it:
| Rate every 8 h | At each payment | Per day | Over 30 days | On 1,000 USDT of margin |
|---|---|---|---|---|
| 0.005% | 0.5 USDT | 1.5 USDT | 45 USDT | 4.5% |
| 0.01% | 1 USDT | 3 USDT | 90 USDT | 9% |
| 0.03% | 3 USDT | 9 USDT | 270 USDT | 27% |
| 0.05% | 5 USDT | 15 USDT | 450 USDT | 45% |
| 0.1% | 10 USDT | 30 USDT | 900 USDT | 90% |
At 0.05% held for a month, almost half the margin goes on funding alone, even if the price doesn’t move. In moments of euphoria the rate goes beyond those values.
The formula I use
- Each payment = position size × rate. 10,000 × 0.01% = 1 USDT.
- Payments = days × 24 ÷ hours between payments. 30 days every 8 hours: 90.
- Total = each payment × payments. 1 × 90 = 90 USDT.
- Share of the margin = total ÷ margin, and the margin is the size ÷ the leverage. 90 ÷ 1,000 = 9%.
With a positive rate, the long pays and the short receives; with a negative rate, the other way round. The calculator puts the sign from your side: negative for what you pay and positive for what you receive. The result of the trade without funding is what the profit and ROE calculator gives you.
The rate changes every period
The exchange recalculates the rate every period from the gap between the perpetual’s price and the spot market price. In calm markets it tends to sit around 0.01%; when many traders are long with leverage, it rises, and it turns negative when shorts dominate.
That is why the calculator’s figure is an approximation: it gives you the order of magnitude before you leave a position open for several days. How it works and who pays whom is in funding rate: what it is in perpetual futures.
Frequently asked questions
How is the funding rate calculated?
What you pay or receive each period is the position size times the rate. With 10,000 USDT and a rate of 0.01%, 1 USDT every 8 hours: 3 a day and 90 over 30 days.
Who pays funding?
When the rate is positive, longs pay shorts; when it is negative, shorts pay longs. It is a payment between traders: the exchange doesn’t keep it.
How often is it charged?
On most perpetuals, every 8 hours. Some contracts charge it every 4 hours or every hour, and the exchange shows this next to the rate.
Is it calculated on the margin or on the position?
On the whole size of the position. That is why, with high leverage, funding takes a large share of the margin.
Do I pay funding if I close before the payment?
No. You only pay or receive it if your position is open at the moment of the payment. If you open and close it between two payments, there is no funding.
Why doesn’t the figure match my exchange?
Because the rate changes every period and the calculator assumes it stays the same. On top of that, the exchange calculates each payment with the value of the position at that moment, which changes with the price.