The Bitcoin network hashrate is an estimate that gauges how much computing power (and thus, miners) are competing for Bitcoin blocks. There’s no way to pull data on the hashrate of all the world’s miners to get a pinpoint figure for the Bitcoin network’s total hashrate. Instead, Bitcoin miners calculate Bitcoin’s estimated total hashrate using Bitcoin’s difficulty and block times.
Hashrate Index charts Bitcoin’s hashrate across three simple-moving-average (SMA) timeframes: 3 days (432 blocks), 7 days (1,008 blocks) and 30 days (4,320 blocks).
The 3 day or 432 blocks timeframe is useful because it is very current. You can easily spot massive disruptions to the Bitcoin mining hashrate from events like China’s Mining Ban, for example. The downside of the 3 day view is that faster or shorter blocks can distort the hashrate estimate, making Bitcoin’s total hashrate appear larger or smaller than it really is.
While less current than the 3 day, the 7 day or 1,008 blocks hashrate metric is less influenced by bitcoin mining luck and block times, and so miners see it as a more accurate estimate. The 7D is the industry standard for hashrate reporting.
Lastly, the 30 day or 4,320 blocks SMA smooths outs most of the noise cause by variance to block times but heavily lags short-term trends.