The metrics investors ask about first
Run a subscription business and you'll hear the same acronyms in every board meeting. MRR, churn, LTV, CAC, NRR. They're not hard, but they depend on each other, and getting one wrong throws off the rest.
The nine calculators on this page take the metrics one at a time. They run in your browser and keep your inputs private, so you can try real numbers.
Revenue and churn
The MRR and churn forecaster projects monthly recurring revenue and annual recurring revenue for 3 to 36 months. You enter new bookings, expansion and churn. Even small changes in churn matter hugely over time. A business losing 5 percent of revenue a month loses nearly half its base in a year.
Net revenue retention measures what happens to a group of customers after a year, counting expansion, contraction and cancellations. NRR above 100 percent means your existing customers grow faster than they leave. Gross revenue retention strips out expansion and shows pure leakage. The calculator draws an MRR waterfall and a 12-month cohort projection.
Both numbers tell you whether growth comes from a leaky bucket or a healthy base.
Unit economics: LTV, CAC and payback
Lifetime value estimates what a customer will pay you in total. The LTV calculator shows four versions at once: simple, gross margin adjusted, discounted and contract-based. Use gross margin LTV for decisions. Revenue isn't profit.
CAC payback tells you how many months it takes to earn back what you spent to win a customer. The calculator gives a simple version and a churn-adjusted one, with health bands and a sensitivity view across five CAC levels. Under twelve months is often considered strong for SMB. Enterprise deals can run longer.
The SaaS Magic Number compares new recurring revenue with the sales and marketing spend from the previous quarter. Above about 0.75 is usually a sign you can spend more on growth. Below 0.5 suggests you should fix efficiency first.
- LTV to CAC ratio near 3 or better is the usual target
- Payback under 12 to 18 months keeps cash healthy
- NRR above 100 percent means expansion beats churn
Pricing and efficiency
The pricing tier optimizer models two or three plans, an annual versus monthly mix, and the MRR and margin each tier contributes. A stacked revenue chart and a mix sensitivity view show how shifting customers from one tier to another changes the total.
Many founders underprice. Raising prices for new customers is cheap to test. If conversions barely move, you were leaving money on the table.
The Rule of 40 visualizer adds ARR growth rate and profit margin. A score of 40 or more is the common benchmark for a healthy software company. It plots your position on a scatter map with 40 and 60 lines, and can track your history by quarter. Early-stage companies often miss it by design, since they trade profit for growth.
Cash and fundraising
The burn rate and runway calculator projects cash month by month with revenue growth, separates gross from net burn and marks the break-even point on a chart. Four scenario rows let you compare plans. Fundraising takes months, so start when you've got twelve or more months of cash, not three.
The Series A dilution calculator shows the pre- and post-money cap tables, the option pool shuffle and how much of the company founders keep. The pool is often created before the round, which means it dilutes existing holders and not the new investors. Many founders miss that on their first term sheet.
How to use them together
Start with churn and NRR. They tell you whether the base is sound. Then calculate LTV and CAC payback to see whether growth pays for itself. Check the magic number to see if sales spend works. Use runway to decide how long you have to fix problems.
Revisit the numbers monthly. Metrics drift, and you want to catch it early.
Caveats
Benchmarks vary by market, price point and stage. The bands here are rules of thumb, not laws. And every definition of ARR, churn or CAC has variations, so write down yours and use it consistently.