Formula

Total Trading Volume = Contract value in opening the position + Contract value in closing the position

Contract Value = Filled Quantity x Filled Price

To calculate trading volume, you need to refer to the trade history:
a. For USDT Perpetual contracts:

The trading volume is calculated by Filled Quantity x Filled Price at the opening and closing of positions.

Please refer to the explanation:

Eg: In a BTCUSDT contract, a trader orders 2 Qty of BTC open at price 25,000 USD and close at price 27,000. The trading volume will be 50,000 for open and 54,000 for the close position, hence the total volume of 104,000 USD.
b. For Inverse contracts:

The trading volume is the Filled Quantity itself.

*Orders only count towards the trading volume if they are executed during the event period, regardless of whether it is an entry order or a closing order.