Tools

CAC and payback calculator.

Acquisition cost on its own says nothing. What matters is the ratio to what the customer is worth — and how long you carry the cost before she pays it back.

CAC

€150

LTV : CAC

1.3×

Lifetime contribution

€192

Payback

17.4 months

A ratio above 1 covers the modelled acquisition cost. A 3:1 ratio is an example, not a guarantee of profitability.

Payback is how long the customer takes to earn back what she cost. It decides how fast you can scale without running out of cash.

Customer contribution over timeSame assumptions as the calculation
━ Cumulative contribution┄ Acquisition cost: 150
0 mo.6 mo.12 mo.18 mo.24 mo.
40 at first purchase192 over the period

Linear illustration with constant contribution per purchase. Actual purchase timing, returns and customer churn can change the outcome.

From insight to action

What does the result mean for you?

Løgbutikken

Website, channels and profit measurement

The Løgbutikken engagement covered the website, email, Meta, Google Ads and ProfitMetrics. The business grew and was subsequently acquired.

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Measurement and customer economics

Discuss measurement and bidding

We review the values you measure and how they can inform budget decisions.

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01What belongs in CAC

Media spend is the obvious part. Agency fees, creative production and the tools used to win new customers belong there too — otherwise the number is prettier than reality.

Divide by new customers only, not by all orders. Mixing repeat purchases in gives an average that describes neither acquisition nor retention.

02Payback and cash flow

Lifetime value tells you whether the customer is profitable. Payback tells you whether you can afford to win her now. Two businesses with the same ratio can have very different room to scale if one recovers the cost on the first order and the other after a year.

A long payback period means growth is financed by cash. That is not wrong, but it should be a decision rather than a surprise.

03The ratio

Assess CLTV relative to CAC using contribution margin, repeat purchases and the time horizon. A rule of thumb such as 3:1 is not a universal target.

A high ratio may leave room to invest more in acquisition. First assess payback, available cash and the expected cost of the next customers.

Questions

What is a good CAC?

One that is low enough against lifetime value and fast enough to recover that cash flow keeps up. A number without both comparisons means nothing.

Should agency fees count towards CAC?

Yes, the share of them that goes to winning new customers. Otherwise acquisition looks cheaper than it is, and scaling decisions rest on the wrong number.

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