# CAC payback

> CAC payback is a unit-economics metric, calculated as CAC ÷ (Monthly ARPA × Gross margin), in months. Whether margin is applied; whether ARPA is new-customer or blended.

Source: https://lopifi.com/glossary/cac-payback
Part of: Lopifi — US GAAP books on autopilot, reviewed by a CPA (https://lopifi.com)

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**What is cac payback?** CAC payback is a unit-economics metric, calculated as CAC ÷ (Monthly ARPA × Gross margin), in months.

## Formula

`CAC ÷ (Monthly ARPA × Gross margin), in months`

## Note

Whether margin is applied; whether ARPA is new-customer or blended

- **Category:** Unit economics
- **Specified in:** [Metric definitions](https://lopifi.com/md/docs/domain/10-metrics)
- **Related:** gross-margin, arpa