LTV : CAC Ratio Calculator

Model customer lifetime value against acquisition cost — with payback period.

Lifetime value

Monthly revenue per account (ARPA)

₹

Gross margin

Monthly churn

Average customer lifetime = 1 ÷ churn.

Acquisition cost

Sales + marketing spend

₹

Total for the period.

New customers acquired

LTV : CAC

6.7 : 1

LTV (gross margin)

₹1,00,000

ARPA × margin × lifetime

CAC

₹15,000

Spend ÷ new customers

CAC payback

5.0 mo

Months to recover CAC

Avg. lifetime

33.3 mo

1 ÷ monthly churn

Healthy — at 6.7:1 each acquisition returns well above the 3:1 rule of thumb. Room to spend more if payback (5.0 mo) stays reasonable.

Uses gross-margin LTV (a conservative, CFO-friendly definition). Assumes steady-state churn and margin.

About this calculator

Estimate gross-margin LTV from ARPA, margin and churn, compute CAC from spend and new customers, and get the LTV:CAC ratio plus CAC payback in months.

Everything runs in your browser — nothing you type is sent anywhere or stored. Use it to sanity-check a plan, pressure-test a channel, or brief a team before you commit budget.