Free tools
Calculators for the numbers you track
12 free calculators, no signup. Each one runs in your browser and explains the formula, what it leaves out, and where the figure usually goes wrong.
Subscription metrics
MRR calculator
Work out monthly recurring revenue from your monthly and annual subscribers, with annual plans normalised to a month.
ARR calculator
Convert monthly recurring revenue to annual recurring revenue, and see what a growth rate does to it over the next year.
Churn rate calculator
Work out customer churn and retention from the customers you started with and the ones you lost, with the annual equivalent.
LTV calculator
Estimate customer lifetime value from average revenue per user, monthly churn and gross margin, with the expected lifetime in months.
CAC payback calculator
Work out how many months it takes to earn back what you spent acquiring a customer, on gross margin rather than on revenue.
Net revenue retention calculator
Work out NRR and gross revenue retention from starting MRR, expansion, contraction and churn, with no new customers counted.
Rule of 40 calculator
Add your growth rate to your profit margin and see whether a software business clears the Rule of 40 benchmark.
Commerce
Marketing and audience
Conversion rate calculator
Work out a conversion rate from visitors and conversions, with the revenue per visitor that makes it comparable across pages.
CTR calculator
Work out click-through rate from clicks and impressions, for search results, ads and email alike.
RPM calculator
Work out revenue per mille from your earnings and views, and see how it differs from the CPM advertisers are quoted.
Payments
Questions
- Are these calculators really free?
- Yes. There is no signup, no email wall and no limit on use. They run entirely in your browser, so nothing you type is sent anywhere or stored.
- Do the calculators store the numbers I enter?
- No. Every calculation happens in your browser. The figures you type never reach a server, which is why there is nothing to sign up for.
- Which calculator should I use for subscription revenue?
- Start with the MRR calculator for the value of your book, then the churn rate calculator and lifetime value calculator to understand what a customer is worth. Net revenue retention is the one investors ask for.
- Can I see these numbers automatically instead of calculating them?
- Yes, that is what Notch Metrics does. Connect Stripe, Polar, Shopify or any of fourteen sources and the figures sit in your MacBook notch, updated on a schedule, with no tab to open.