Understanding SaaS Rule of 40
How we calculate. Score = growth % + profit margin %. See our methodology and accuracy policy .
Real-world scenario: A typical SaaS Rule of 40 case uses revenue growth % 25 and profit margin % 18. Enter the same figures below to reproduce the worked path.
What is SaaS Rule of 40?
A balanced growth-vs-profitability KPI. Distinct from finance Rule of 72 and from SaaS magic number.
- Growth % = revenue growth for the period
- Margin % = profit / operating margin per policy
- Same period
The Formula
Worked Example
Common Use Cases
- Board packs: growth + margin balance
- Peer comps: Rule of 40 screen
- Strategy: growth vs profitability trade-off
Pro Tips
- Freeze margin definition (operating vs free cash flow)
- Don’t use Rule of 72
- Pair with magic number
| Scenario | When to use |
|---|---|
| Percent of a number | Finding a part of a whole (tax, tip, score) |
| Percent change | Comparing old vs new values |
Limitations: SaaS Rule of 40 results are educational SaaS / subscription planning aids—not accounting, tax, or investment advice. Confirm definitions with your billing system and board reporting standards.
Common mistakes
- Swapping part and whole: The denominator must be the full total, not a subset.
- Rounding too early: Carry extra decimal places through multi-step work before rounding the final percent.
- Mixing percent and decimal forms: Enter rates in the format the calculator labels expect.
The worked example for saas rule of 40 was verified with the calculator form on this page—enter the same values to confirm the result.
When to use this calculator
- Use this page when your wording matches saas rule of 40 and the form labels on screen.
- Use percent of a number for “what is X% of Y?” problems.
- Use number is what percent when you know part and whole and need the percent.
Still unsure about saas rule of 40? Start with the quick answer above, then open the linked calculator that matches your wording.
❓ Frequently Asked Questions
How do I use this saas rule of 40 calculator?
For saas rule of 40, enter the values labeled on the form, then press Calculate. Compare the result to the worked example on this page.
What formula does this page use?
See the quick answer and formula box above for saas rule of 40—the same percentage calculator expression is applied to your inputs.
What if my result looks wrong?
When checking saas rule of 40, re-check part vs whole (or rate vs base), rounding, and whether percents were entered as 25 rather than 0.25 when the form expects percents.
Authoritative References
For SaaS metrics and subscription performance concepts, consult:
- SaaStr — SaaS growth and metrics context
- For Entrepreneurs — SaaS metrics explainers
- Bessemer Venture Partners — cloud / SaaS industry research