How does one work out hashrate based on number of submitted shares

Question

We are running a pool and are trying to get a total hashrate estimate. How can we figure out how many hashes are being submitted to the pool based on the shares submitted?

Answer 1

A share has more often than not the maximum Target value (as in Difficulty 1). To create a share one needs on average 2^32 tries, or hashes. Multiply the number of submitted shares by 2^32, divide over the period those shares were submitted in and you have your hashrate estimate.