Customer acquisition cost (CAC) calculator.

How this calculator works (same formula nouz uses)

Customer acquisition cost (CAC) is what you pay, on average, to win one new customer. On its own it means nothing — €50 is cheap for a furniture store and lethal for a coffee subscription. The number that matters is the ratio between the value a customer brings (LTV) and what they cost to acquire (CAC). This calculator gives you both the CAC and that ratio.

In plain English: CAC = total marketing spend ÷ new customers acquired, and LTV:CAC ratio = LTV ÷ CAC. "Marketing spend" means all of it for the period — ad spend, agency and freelancer fees, content production, influencer payments, and the marketing tools you pay for.

A worked example

Using the defaults — €4,800 of marketing spend, 100 new customers, and a customer LTV of €312:

• CAC: €4,800 ÷ 100 = €48 per customer
• LTV:CAC ratio: €312 ÷ €48 = 6.5 : 1

A 6.5:1 ratio is well above the healthy 3:1 floor — so far above that it often signals you could spend more aggressively and still win customers at a good return, rather than a reason to celebrate and coast. Work it the other way to see the room you have: at an LTV of €312 the 3:1 rule allows a CAC up to €104, and your actual €48 is less than half of that ceiling. That gap is your budget headroom — the amount you could let CAC rise while chasing more customers before the economics turn tight.

What a healthy number looks like

Read CAC entirely through the ratio:

• Under 1:1 — you lose money on every customer. Stop scaling until the economics work.
• 1:1 to 3:1 — roughly break-even. There is little cushion for overhead or attrition.
• 3:1 — the healthy floor. Scale the channels that hit it.
• 5:1 and above — often a sign you are under-investing; a bigger budget may capture more of the market at still-healthy returns.

The 3:1 target exists because lifetime value is a forecast, not a guarantee — the extra margin absorbs shorter-than-hoped lifespans and customers who churn early.

Common mistakes

• Counting ad spend only. Leaving out agencies, freelancers, content and your own time produces a flatteringly low CAC that hides a money pit.
• Comparing CAC to AOV instead of LTV. A first order rarely pays back acquisition; the customer's whole lifetime does.
• Blending channels. One efficient channel can mask several loss-making ones inside a single average CAC.
• Judging CAC without a ratio. A number with no LTV beside it cannot tell you whether growth is making you richer or poorer.

When to use it — and what's next

Check CAC every period, and any time you add a channel or change your budget. There are two honest ways to lower it: improve conversion so the same traffic yields more customers, or tighten targeting so you waste fewer clicks — both beat simply "spending less on ads", which usually just slows growth without fixing the underlying inefficiency. Because nouz is a simple daily profit tool and does not pull spend from ad platforms, you total your marketing costs and enter them yourself — which is also what forces you to count the costs a dashboard would miss. If you do not yet have a reliable LTV to compare against, build one first with the sibling customer lifetime value calculator, then bring that number back here.