The network hash rate at any specific block height can be checked by running the following RPC command in a console, terminal, or API request (example for block height 984027): getnetworksolps 0 984027. The value returned is solutions (hashes) per second. Note that a zero is passed as the first parameter to return the hash rate for a specific block height rather than the average of last n blocks from block height. If you’re bad at math, you can use this calculator to convert the value returned.