How Is the Funding Rate Calculated on Most Crypto Exchanges?
The funding rate is typically calculated using a formula that considers the difference between the perpetual contract's price and the spot index price, often called the 'premium index'. This premium is then adjusted by an 'interest rate component' to reflect borrowing costs.
The calculation occurs at regular intervals, usually every eight hours. If the perpetual price is higher than the spot price, the rate is positive; if lower, it is negative.