MQL (Marketing Qualified Lead) to SQL (Sales Qualified Lead) conversion rate is the percentage of MQLs that are converted to an SQL. An MQL is a lead that marketing believes meets the criteria of a qualified prospect, and an SQL is a lead that sales has independently qualified and believes meets the criteria of a qualified prospect.

A Marketing Qualified Lead (MQL) is a universal metric used by marketing teams to measure the quality of leads they generate and pass to sales. Most marketing teams have targets associated with MQLs that include number of MQLs and acceptance rate, for example, leads that go on to become Sales Accepted Leads.