CPL & CPA Calculator
Cost per lead, cost per acquisition, and the true cost behind your funnel.
Every $400 lead is worth watching, at a 12% close rate it takes about 8 leads and $3,333 in spend to land one customer.
About this calculator
Cost per lead only tells half the story, a channel with a cheap CPL that rarely converts to a customer can cost more per acquisition than a pricier channel that closes reliably. This calculator takes spend, lead volume and your lead-to-customer rate and gives you both numbers side by side, so a channel comparison isn't decided on CPL alone.
How to use it
- Enter total ad spend for the period and the number of leads it generated.
- Enter your lead → customer conversion rate, the share of those leads that became paying customers.
- Read cost per lead (spend ÷ leads) and cost per acquisition (spend ÷ customers), the number that actually reflects what a new customer costs.
Methodology
Cost per lead (CPL) is spend ÷ leads generated, a straight average cost across all leads regardless of what happens to them afterward.
Customers is leads × lead-to-customer conversion rate, the number of leads from this spend that are expected to become paying customers.
Cost per acquisition (CPA) is spend ÷ customers, always higher than CPL whenever the conversion rate is below 100%, since CPA spreads the same spend across a smaller surviving number.
This treats spend, leads, and conversion rate as belonging to a single period and channel. Mixing spend from one period with lead-to-customer rates measured over a longer window (since deals take time to close) will distort the CPA figure, match the time windows as closely as possible.
FAQ
Because not every lead becomes a customer. CPA divides the same total spend across a smaller number, customers instead of leads, so it will always be equal to or greater than CPL, and often several times higher when conversion rates are in the single digits.
Run its actual lead-to-customer rate through this calculator. A channel with a cheap CPL and a weak conversion rate frequently loses on CPA to a more expensive channel with better-qualified leads, comparing CPL alone hides that.
Use a rolling average over 3-6 months where possible, single-month lead-to-customer rates can be noisy, especially for sales cycles that stretch across multiple months, since leads from one month often close in a later one.