Rule of 40 Calculator
SaaS growth-profit balance.
Calculate the SaaS Rule of 40 score by summing revenue growth rate and profit margin — the threshold investors use for healthy SaaS.
What this tool does
The Rule of 40 combines a company's revenue growth rate and profit margin into a single score that reflects the balance between expansion and profitability. The calculator adds these two percentages together to produce a result of 40 or above, which typically indicates a healthy equilibrium in the growth-versus-profitability tradeoff. Both inputs—revenue growth rate and profit margin—carry equal weight in determining the final score. This metric is commonly used to evaluate SaaS and subscription business models, where companies often face tension between investing in growth and maintaining operational efficiency. The score illustrates where a business sits on this spectrum and can be used to compare performance across periods or against peer companies. Results are for educational illustration and do not account for factors like market conditions, cash flow, or debt levels.
Enter Values
Value is unusually high — please double-check
People also use
Business & Startup
EBITDA Margin Calculator
Calculate EBITDA margin from EBITDA and revenue to measure operating profitability before financing and tax structure differences.
Business & Startup
Revenue Growth Rate Calculator
Calculate revenue growth rate between two periods, expressed both as a percentage and as a multiple of the prior period's number.
SaaS & Subscription
SaaS Rule of 40 Calculator
Calculate the SaaS Rule of 40 — revenue growth rate plus profit margin should sum to at least 40 to qualify as a healthy SaaS business.
Formula Used
Spotted something off?
Calculations or display — let us know.
Disclaimer
Results are estimates for educational purposes only. They do not constitute financial advice. Consult a qualified professional before making financial decisions.
The Rule of 40 sums a SaaS company's growth rate plus profit margin. A score at or above 40% signals balanced performance - either growing fast with some profit, or growing modestly but very profitably. Below 40% usually means the business is either overspending for growth or underinvesting while profitable. Benchmark for public SaaS valuation.
40% growth rate + 10% profit margin = 50% Rule of 40 score. Strong. The business balances growth and profitability well. A 20% growth rate + 30% margin also hits 50 - same Rule of 40 score but different business profile (slower but much more profitable). Investors care about the total; strategic decisions flow from which side to emphasise.
Early-stage SaaS often posts 100% growth with -50% margin (Rule of 40 = 50), which is healthy. Late-stage SaaS runs 20% growth with 20% margin (Rule of 40 = 40), also healthy. Companies at 20% growth with 0% margin (Rule of 40 = 20) are usually penalised by markets - they're neither growing fast nor generating cash. Rule of 40 exposes this neither-nor trap.
Run it with sensible defaults
Using revenue growth rate of 40%, profit margin of 10%, the calculation works out to 50.00%. The defaults are meant as a starting point, not a recommendation.
The levers in this calculation
The inputs — Revenue Growth Rate % and Profit Margin % — do not pull with equal force. Not every input has equal weight. Adjusting one input at a time toward extreme values shows which ones move the result most.
How the math works
Rule of 40 = growth rate % + profit margin % (as a single additive score).
Using this as a check-in
Re-run this every three months. A single reading tells you where you stand; four readings tell you whether things are improving. The trend matters more than any individual snapshot.
What this doesn't capture
The score is a composite of the inputs you provide. Life context — job security, family obligations, health, housing — doesn't appear in the math but shapes the real picture. Use the number as a prompt, not a verdict.
40% growth + 10% margin = 50.00%.
Inputs
This example uses typical values for illustration. Adjust the inputs above to match a specific situation and see how the result changes.
Sources & Methodology
Methodology
The calculator computes the Rule of 40 score by adding two inputs: the revenue growth rate (expressed as a percentage) and the profit margin (expressed as a percentage). The result represents a single composite metric commonly used to assess the balance between expansion and profitability in subscription and software businesses. The model assumes both inputs are reported on a consistent basis and uses simple addition without weighting or adjustment. It does not account for differences in accounting method, market conditions, business stage, or the sustainability of reported figures. The score itself is descriptive only and does not predict future performance or validate the underlying business model.
References
Frequently Asked Questions
Which margin to use?
Is 40 the magic number?
Rule of 40 vs absolute growth?
What if score is below 40?
Related Calculators
EBITDA Margin Calculator
Calculate EBITDA margin from EBITDA and revenue to measure operating profitability before financing and tax structure differences.
Revenue Growth Rate Calculator
Calculate revenue growth rate between two periods, expressed both as a percentage and as a multiple of the prior period's number.
SaaS Rule of 40 Calculator
Calculate the SaaS Rule of 40 — revenue growth rate plus profit margin should sum to at least 40 to qualify as a healthy SaaS business.
More SaaS & Subscription Calculators
SaaS & Subscription
Annual Recurring Revenue Growth Calculator
Calculate your annual recurring revenue growth rate year-over-year and track absolute ARR added — the core SaaS metric investors review first.
SaaS & Subscription
ARPU Calculator
Calculate ARPU by entering total revenue and active user count to see average revenue per user monthly and annualised instantly.
SaaS & Subscription
ARR Calculator
Calculate current ARR and forecast future ARR using your MRR and monthly growth rate over a 12 to 24 month projection horizon.
SaaS & Subscription
ARR Payback Period Calculator
Calculate ARR payback period using total CAC spend, new ARR added, and gross margin to estimate months until acquisition costs are recovered.
SaaS & Subscription
CAC Payback Period Calculator
Calculate CAC payback period in months from customer acquisition cost, MRR per customer, and gross margin on the contract.
SaaS & Subscription
Churn Rate Calculator
Calculate churn rate and net growth rate from starting customers, customers churned, and customers gained during the period.
Explore Other Financial Tools
Mortgage
Buy to Let Affordability Calculator
Calculate buy-to-let affordability using interest cover ratio (ICR) and stress-tested rate. Enter property price to see icr and stress-tested affordability.
Psychology & Behavioral
Alcohol Annual Spending Calculator
Annual and lifetime cost of regular alcohol drinking plus what investing the same money could become at compound returns over decades.
Hospitality
Hotel ADR Calculator
Calculate hotel ADR, RevPAR, and occupancy from revenue and rooms data. Enter room revenue, rooms sold, rooms available, and period to size hotel performance.