How to calculate Lead Conversion Rate

Formula

Lead conversion rate = leads converted ÷ leads created × 100

SQL query

This example assumes: leads(id, source, created_at, converted_at). It is written in PostgreSQL syntax; date functions differ slightly in MySQL, BigQuery and SQLite, and your column names will differ from these.

SELECT source,
       COUNT(*)                                   AS leads,
       COUNT(converted_at)                        AS converted,
       COUNT(converted_at) * 100.0 / NULLIF(COUNT(*), 0) AS conversion_pct
FROM leads
WHERE created_at >= DATE '2026-07-01' AND created_at < DATE '2026-10-01'
GROUP BY source
ORDER BY conversion_pct DESC;

Common mistakes that make Lead Conversion Rate wrong

• Recent leads have had less time to convert, so the latest month always looks worse; use a fixed window such as 30 days from creation.
• Counting duplicate leads for the same person inflates the denominator.
• Sources with very few leads show extreme rates; show the counts.

Ask for Lead Conversion Rate in plain English

Instead of writing the query yourself, you can type the question. SchemaChat turns it into SQL against your connected database or uploaded file, runs it, and shows the SQL and the figures it used so you can check the answer before you share it. It does not replace your judgement about the definition: check that the query matches the formula your business uses.

• What is our lead conversion rate by source for last quarter?
• Which lead sources convert best within 30 days?