CAC Payback Calculator
This calculator won't make your metrics look good.
It's designed to tell you if your company survives until the next round.
Google Sheets. No signup tricks. Just honest math.
You're probably calculating CAC wrong:
- •Blending organic and paid signups into one number that hides the truth
- •Using revenue instead of gross profit to calculate payback
- •Forgetting that your "free" organic channel costs founder time and salaries
- •Assuming customers stay for 3 years based on 4 months of data
The founders who make it aren't the ones with the best numbers. They're the ones who understand their numbers.
What You Get
The CAC Payback Calculator shows you three layers:
- ✓Blended CAC and Payback (the headline number everyone asks for)
- ✓Paid CAC and Payback (is your paid acquisition actually sustainable?)
- ✓Organic CAC and Payback (what does "free" really cost when you include labor?)
Plus:
- ✓Real gross margin calculation (hosting, Stripe, support labor included)
- ✓Instant diagnostics (green, warning, or death zone for each metric)
Why Three Layers Matter
Most founders only know their blended CAC. That's the surface.
Investors ask about CAC. The best founders can answer at three levels: blended, by channel, and on gross profit.
A €50 blended CAC looks great until you realize your paid CAC is €500 and organic is doing all the work. That's not a scalable business. That's a lucky accident.
This calculator separates the layers so you can see what's actually working and what's bleeding cash.
Who This Is For
You've raised pre-seed or seed (€500K - €3M).
You're spending on acquisition but not sure which channels are actually working.
You have a CAC number in your pitch deck but you've never stress-tested it.
You want to walk into investor meetings knowing your numbers are real, not hoping nobody asks the hard questions.
This Is Free. Here's Why.
I'm Judie. I help seed-stage founders fix their unit economics before it's too late.
Most founders don't know their real payback period. They calculate with flattering assumptions and wonder why the runway disappears faster than expected.
This calculator forces honest inputs. The number will probably be higher than you want. That's the point.
Better to know now than to find out mid-raise when an investor asks how you calculated your CAC.
FAQ
Know your numbers before someone else asks.
You'll get it in 2 minutes. Then you'll know if your unit economics are real.
P.S. The founders who use this aren't hiding from their metrics. They're the ones who make it.