See the formula, not just a score
CAC, LTV, break-even, and runway, calculated live from your own numbers with a real formula behind every result. No opaque AI score, no signup required.
Want to validate your own idea or pain point instead? Generate & Validate →
Every number traces back to a real formula
Most idea validators hand you a single AI-generated score and ask you to trust it. Ours shows the actual formula behind every metric, with your own inputs plugged in, so you can check the math yourself.
Customer lifetime value
For a subscription business: monthly revenue per customer, times gross margin, divided by monthly churn.
LTV alone doesn't tell you much — it only becomes a health signal once you compare it to CAC below.
CAC payback period
How many months of gross margin it takes to earn back what you spent acquiring one customer.
A commonly cited target for subscription businesses is 12 months or less — the faster you earn it back, the sooner that cash is free to reinvest in growth.
Break-even point
Your fixed monthly costs, divided by the margin each customer contributes, tells you how many customers you need.
Compare this number against realistic monthly signups for your market — if break-even needs more customers than the whole addressable market, that's worth knowing before you build.
Cash runway
What you have in the bank, divided by what you spend each month, tells you how long you can keep going.
Most founders raising or fundraising again aim to start that process with 6+ months of runway left, not zero.
These four are the core Unit Economics and Financial Health calculators, free and open to everyone. Plug in your own numbers and every formula above recalculates live.
The numbers you plug in are yours. The benchmarks they're compared against are drawn from 16,000+ ideas evaluated on IdeaCrawl, not industry averages from a textbook.
Reading the four numbers together
Say you're pricing a SaaS product at $49/month with a 70% gross margin, and it costs you $150 to acquire a customer through paid ads. On their own, none of these numbers say much. Together, they tell a story.
LTV comes out to $686 against a $150 CAC — an LTV:CAC ratio of about 4.6:1, comfortably above the 3:1 rule of thumb. CAC payback lands at 4.4 months, well inside the 12-month target, so that $150 isn't tied up for long. With $5,000 in fixed monthly costs, break-even sits at 146 paying customers — a number you can immediately sanity-check against how many people in your target market you can realistically reach in a given month. And with $50,000 in the bank against $8,000/month in spend, you have roughly 6.3 months of runway to hit that 146-customer mark before you need to raise again or cut costs.
Change any one input — a higher CAC from a saturated ad channel, a lower price point, slower signups — and every downstream number shifts with it. That's the point of seeing the formula: you're not reading a verdict, you're reading a model you can stress-test with your own assumptions.
What's free
- • Every calculator, with instant results, no signup required
- • Unit economics: LTV, CAC payback, LTV:CAC ratio
- • Financial health: break-even point and cash runway
- • Matching against the top 10 closest ideas already in the catalog
What requires a plan
- • The Hidden Opportunity Detector and Business Personality analysis
- • The Investor View and plain-language Explain-Why breakdown
- • Unlimited idea matching, beyond the free top 10
Signing up free (no plan required) also lets you save and share a snapshot of your results.
Jump straight to a calculator
Don't have numbers to plug in yet? Generate a free business plan first, or browse 16,000+ real pain point ideas already validated for their own numbers. For a sense of what strong margins look like at scale, see High Pricing Power Ideas. Want to research your market without leaving a trace first? Try our private search engine - same no-tracking philosophy as the calculators above.
Frequently asked questions
Why show the formula instead of just a score?
A single score can't be checked - you either trust it or you don't. Showing the formula (LTV = monthly revenue per customer times gross margin, divided by monthly churn, for example) means you can verify the result by hand and see exactly which input to change if the number looks wrong.
What's a healthy LTV:CAC ratio?
A commonly cited rule of thumb is 3:1 or higher - meaning a customer is worth at least three times what it costs to acquire them. Below that, growth tends to eat itself; well above 5:1 can sometimes mean you're underinvesting in acquisition rather than that things are going unusually well.
What's considered a healthy CAC payback period?
For most subscription businesses, 12 months or less is the commonly cited target - it means the gross margin from a customer earns back what you spent acquiring them within a year, leaving cash free to reinvest in growth sooner rather than later.
Do these calculators account for my specific industry?
The four core formulas - LTV, CAC payback, break-even, and runway - are standard finance math that applies the same way regardless of industry; you supply the inputs for your business. Where industry does matter is the idea-matching feature, which compares your numbers to similar ideas already in IdeaCrawl's catalog based on business model and pricing, not a generic industry average.
Is this a replacement for an accountant or financial planning software?
No. It's a fast way to sanity-check your numbers before you invest time building a full financial model or paying for advice - useful for an early gut check, not a substitute for proper accounting or a fundraising-grade financial plan.
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