Free SaaS metrics calculators for the numbers that decide growth: CAC, LTV, churn, NRR, Rule of 40, valuation and more. Each gives an instant result with a plain-English read on what it means. They run in your browser, so nothing you enter is stored.
The numbers that decide whether a SaaS grows or stalls are not complicated but they are easy to guess at and easy to get wrong. These 14 free SaaS metrics calculators give you the real figure in seconds, plus a plain-English read on what it means. No signup, no email gate, nothing stored. They run entirely in your browser.
We built them because we are a SaaS marketing agency and these are the metrics we work in every day. A CAC measured on media spend alone, an LTV based on revenue instead of margin, a churn rate read without its retention mirror: each of these quiet errors sends budget the wrong way. The calculators use the standard formulas and tell you the honest version.
Use any of them on their own, forever, for free. They stand alone whether or not you ever talk to us. And if the numbers point to a growth problem we can help with, the audit is one click away but that is your call, not the price of the tool.
Work out fully loaded customer acquisition cost in seconds and see what it signals.
Open the calculator →Margin-adjusted lifetime value from your ARPA, margin and churn.
Open the calculator →Divide lifetime value by acquisition cost to read growth efficiency in one number.
Open the calculator →How many months it takes to earn back what you spent winning a customer.
Open the calculator →How much new ARR each dollar of sales and marketing spend produces.
Open the calculator →Add growth rate to margin and see if you clear the 40% investor bar.
Open the calculator →Compare MRR gained against MRR lost to judge how durable your growth is.
Open the calculator →Year-over-year ARR growth from starting and ending revenue.
Open the calculator →The percentage of customers or revenue you lose over a period.
Open the calculator →Whether your existing base grows itself through expansion, after churn.
Open the calculator →Project recurring revenue 12 months out from bookings and churn.
Open the calculator →A sensible marketing spend range from your ARR and growth target.
Open the calculator →Return on ad spend, with the caveat every B2B SaaS marketer needs.
Open the calculator →Estimate a valuation range from ARR, growth and net revenue retention.
Open the calculator →The biggest mistake with SaaS metrics is reading one in isolation. A low CAC looks great until you see the churn rate eating the base you paid to build. A high growth rate looks healthy until the quick ratio shows you are losing almost as much as you gain. The calculators are individually useful but the real signal comes from how they sit together.
Three of them form the core unit-economics picture: CAC, LTV and payback period. Read those as a set and you know whether a customer is worth more than they cost and how fast you get your money back. Then layer in retention, churn and net revenue retention, because a customer base that grows itself changes every other number on the page. Efficiency metrics like the magic number and Rule of 40 sit on top, telling you whether to spend more or fix the engine first.
So use them as a panel, not a single gauge. Run your CAC, then your LTV, then the ratio between them. Check churn, then check NRR to see whether expansion offsets it. The story that emerges across four or five of these tools is far more honest than any one number and it is usually the story that tells you where your real growth problem sits.
We offer 14 free SaaS metrics calculators covering the numbers that matter most: CAC, LTV, the LTV to CAC ratio, CAC payback period, the magic number, Rule of 40, quick ratio, ARR growth rate, churn rate, net revenue retention, MRR forecast, marketing budget, ROAS and SaaS valuation. Each runs in your browser, gives an instant result with a plain-English interpretation and explains the formula behind it. No signup is required.
Yes, completely free with no signup, no email gate and no catch. Every calculator runs entirely in your browser, so nothing you enter is sent anywhere or stored. We built them because the SaaS metrics that decide growth are too often guessed at and a fast, honest calculator beats a back-of-envelope estimate. If your numbers reveal a marketing problem, we are happy to help but the tools cost nothing to use.
The formulas are the standard, widely accepted SaaS definitions, so the math is accurate. The interpretation thresholds, like what counts as a healthy magic number or a good churn rate, are benchmark ranges drawn from common industry experience rather than rules that fit every business. Use the calculated number as solid and treat the interpretation as a sensible starting point you adjust for your stage, segment and model.
Start with the metric that matches your current question. If you are wondering whether growth is efficient, use the LTV to CAC ratio or the magic number. If you are worried about retention, start with churn rate and net revenue retention. If you are planning spend, the marketing budget and MRR forecast tools help. Most SaaS benefit from reading CAC, LTV and payback together, since those three tell the core unit-economics story.
No. The calculators only ask for the figures needed to compute a metric, like spend, revenue or churn and everything runs locally in your browser. Nothing is transmitted, logged or stored, so you can use real numbers safely or test with estimates. There is no account, no tracking of your inputs and no way for the figures to leave your device, which is exactly how a free tool should work.
TG3 built them. We are a SaaS marketing agency that works only with SaaS companies across every stage from Series A to public, so these are the metrics we live in every day. We built the calculators to be genuinely useful on their own, whether or not you ever talk to us. If the numbers point to a marketing or growth problem we can help with, the audit is there but the tools stand alone.
Yes. The metrics apply across stages, though the healthy benchmarks shift as you grow. An early-stage SaaS reads churn and CAC differently from a public company, which is why each calculator gives interpretation context rather than a single pass-fail verdict. Whether you are a Series A founder checking payback or a CFO modelling valuation, the calculators work and the interpretation notes help you read the result for your stage.
If your CAC, churn, payback or NRR is not where it should be, that is usually a marketing problem we fix. Book a 30-minute audit and we will tell you which lever moves first. No sales sequence.
Book the 30-minute audit →