Input accuracy
Are you using real, current numbers — not rough guesses that flatter the result?
Skip or Ship — Free Calculators
CAC Calculator
Calculate your customer acquisition cost, LTV:CAC ratio, and CAC payback period. Free CAC calculator for startups and SaaS businesses.
Benchmark fit
Is your result healthy for your specific business model, not just positive?
Sensitivity
Which single input, if wrong, would change the result most?
Time horizon
Does this hold up over 12 months, or only at today's volume?
Next decision
What should change in the business because of this number?
CAC tells you what it actually costs to win a customer — including every marketing dollar, every sales salary, and every tool that touches the acquisition funnel, not just the ad spend line.
This calculator also computes your LTV:CAC ratio and payback period, the two metrics that determine whether your acquisition spend is sustainable at scale.
Free calculator
Customer acquisition cost (CAC) calculator
Work out what it costs to acquire one customer, and whether your LTV:CAC ratio and payback period are healthy.
£
£/mo
%
£
Results
CAC£200
LTV : CAC ratio6.0:1
CAC payback period5 months
A good number doesn't mean a good idea.
Get the full Ship, Fix, or Skip verdict — free, 30 seconds, no signup.
What to include in CAC
Total sales and marketing spend for the period — ad spend, sales salaries and commissions, marketing tool subscriptions, content and creative production cost. Founders routinely undercount CAC by excluding salaries, which makes acquisition look far cheaper than it is.
Payback period vs LTV:CAC ratio
LTV:CAC tells you if the unit economics work over the customer's full lifetime. Payback period tells you how long you're cash-negative on that customer before recovering the acquisition cost — critical for cash-constrained startups even when the lifetime economics look fine.
How this calculator works
- Enter total sales and marketing spend for the period.
- Enter the number of new customers acquired from that spend.
- Optionally enter ARPU, gross margin, and known LTV to see ratio and payback.
- The calculator shows CAC, LTV:CAC ratio, and payback period in months.
Direct answer — CAC Calculator
Calculate your customer acquisition cost, LTV:CAC ratio, and CAC payback period. Free CAC calculator for startups and SaaS businesses.
Stop reading. Get your verdict.
Describe your idea and the Skip or Ship engine returns a Ship, Fix, or Skip verdict with a full 10-category score breakdown — free, in 30 seconds, no signup.
Frequently asked questions
How do I calculate CAC?
CAC = Total Sales & Marketing Spend ÷ New Customers Acquired, for the same period. Include salaries, tools, and commissions — not just ad spend. Enter both numbers above for the exact figure plus your LTV:CAC ratio and payback period.
What's a healthy CAC payback period?
Under 12 months is the common benchmark for venture-backed SaaS; under 6 months is considered excellent. Longer payback periods require more capital to fund growth and increase risk.
Should I calculate CAC by channel?
Yes, ideally. Blended CAC across all channels hides which channels are actually efficient — a paid channel with 3x the CAC of an organic channel might still be worth scaling if it has better volume ceiling.
Why is my CAC increasing over time?
Common causes: channel saturation (you've exhausted the cheap early-adopter audience), rising ad auction competition, or sales-cycle lengthening as you move upmarket. Track CAC trend monthly, not as a single static number.
Related pages
Last reviewed
Ready to pressure-test this idea with live market signals?
Validate your idea now