Lead conversion calculator: turn funnel rates into revenue math

Lead conversion without fuzzy definitions

Conversion rate only works when stage definitions are shared. MQL, SQL, opportunity, and customer must mean the same thing to marketing and sales or the calculator will start fights instead of ending them.

SchemaDesk frames this page as a free how-to-calculate guide for funnel math that will later power an interactive conversion tool.

Conversion formulas

Stage conversion = (records that reached next stage ÷ records that entered this stage) × 100 in the same cohort window. Overall lead-to-customer rate = (customers ÷ new leads) × 100 for that cohort.

Expected customers = leads × lead-to-MQL × MQL-to-SQL × SQL-to-opportunity × opportunity-to-close. Multiply the decimals, then scale by average deal value for revenue expectation.

• Always cohort by lead create date
• Do not mix in-period stage moves from older leads into new-lead rates
• Report both conversion and volume; a high rate on tiny volume misleads

Inputs to gather

Export or report each stage count for one cohort month or quarter. Document the exact field or status that defines each stage.

• New leads in the cohort
• Count reaching MQL, SQL, opportunity, and closed-won
• Average deal value for closed-won from that cohort
• Sales cycle lag so you wait long enough before judging the cohort
• Channel split if blended rates hide a broken source

Worked example

In January, 2,000 leads enter. 400 become MQLs (20%), 160 become SQLs (40% of MQLs), 80 become opportunities (50% of SQLs), and 20 close (25% of opportunities). Lead-to-customer = 20 ÷ 2000 = 1%.

At $6,000 average value, expected revenue from the cohort is 20 × $6,000 = $120,000. If SQL-to-opportunity rises from 50% to 60% with better qualification, opportunities become 96 and closed-won at the same 25% becomes 24, or $144,000, a $24,000 lift without more top-of-funnel spend.

From conversion math to SchemaDesk

Conversion leaks often come from unclear ownership and stages that live in chat instead of the CRM. SchemaDesk free buyer guides quantify the leak; teams ready to implement can model stages and handoffs in a customizable workspace.