LTV to CAC Payback Calculator

About this calculator

CAC payback period measures how many months it takes a subscription business to recover what it spent to acquire a customer: payback months = CAC ÷ monthly gross margin per customer. A shorter payback period means cash tied up in acquiring customers gets freed up faster to reinvest in growth.

Alongside payback, the LTV to CAC ratio (customer lifetime value divided by acquisition cost) checks whether a customer is worth acquiring at all over their full relationship with the company — investors commonly look for a ratio of at least 3:1 as a sign of a healthy, scalable business model. SaaS founders, growth teams, and venture investors use both metrics together to judge whether marketing and sales spend is generating durable value. This calculator takes CAC, monthly gross margin per customer, and customer LTV to return the payback period and LTV:CAC ratio.