SaaS Metrics Calculator: MRR, ARR, LTV, CAC, Churn and More
Enter your key subscription data and get the full picture of your SaaS business health: monthly and annual recurring revenue, customer lifetime value, CAC payback period, net revenue retention, Rule of 40 score, and the SaaS magic number. Each result includes an industry benchmark so you know exactly where you stand.
The core SaaS metrics and what they measure
Monthly Recurring Revenue (MRR) is the predictable revenue normalized to a month from all active subscriptions. Annual Recurring Revenue (ARR) is simply MRR multiplied by 12 and is the standard headline number for SaaS businesses because it strips out one-time revenues and shows the sustainable baseline. Customer Lifetime Value (LTV) estimates the total gross profit a single customer generates from sign-up to cancellation, calculated as ARPU multiplied by gross margin divided by the monthly churn rate. The LTV:CAC ratio compares that lifetime value against the cost to acquire the customer; a ratio of 3x or above is the widely accepted benchmark for a healthy, scalable growth engine. CAC Payback Period measures how many months of gross margin it takes to recover the cost of acquiring a customer, and most investors target under 18 months. Net Revenue Retention (NRR) tracks what percentage of revenue from your existing customer base you retain after accounting for churn, downgrades, and upsells: an NRR above 100% means your existing customers are expanding faster than they churn, which is the hallmark of a truly compounding SaaS business.
Rule of 40 and the SaaS Magic Number
The Rule of 40 is a heuristic popularized by Brad Feld and widely used by investors to evaluate whether a SaaS company is balancing growth and profitability efficiently. You add the annual revenue growth rate to the profit margin (or subtract the loss margin). A score above 40% signals the business is healthy whether it prioritizes growth or profitability. Early-stage companies often score below 40% while investing heavily in growth, but mature SaaS businesses are generally expected to clear this threshold. The SaaS Magic Number measures sales efficiency by dividing the new gross-profit ARR added in a quarter by the sales and marketing spend in the prior quarter. A magic number above 0.75 suggests your go-to-market motion is efficient and worth doubling down on. Above 1.0 is exceptional. Below 0.5 suggests the cost of growth is too high relative to the revenue it generates, which often points to a need to rethink targeting, positioning, or the sales process before scaling spend.
How churn compounds and why it matters more than it looks
Monthly churn looks small in isolation but compounds heavily over a year. A 5% monthly churn rate does not equal 60% annual churn: it equals 1 - (1 - 0.05)^12, which is approximately 46%. This means nearly half your customer base turns over every year, making it extremely expensive to grow because you are constantly refilling a leaking bucket. Reducing monthly churn from 5% to 2% cuts annual churn from 46% to about 22%, roughly doubling the average customer lifetime and therefore the LTV. Expansion revenue partially offsets this: if existing customers spend more over time through upsells, cross-sells, or seat expansion, your net revenue retention can exceed 100% even with meaningful logo churn. The best SaaS businesses combine low logo churn with high net dollar retention, so their revenue base grows organically without needing to win new customers to replace lost revenue.
How to improve each metric
To increase MRR, raise ARPU through price increases or by packaging more value into higher tiers, or grow the customer count by improving top-of-funnel and conversion rates. To improve LTV, focus on reducing churn through better onboarding, customer success, and product-market fit signals, or increase gross margin by reducing hosting and support costs. To lower CAC, tighten targeting, invest in content and SEO for lower-cost inbound acquisition, and reduce sales cycle length by improving demo-to-trial conversion. To improve NRR above 100%, build a systematic expansion motion: usage-based pricing, seat expansion, or complementary product modules. To improve your Rule of 40 score, either accelerate growth (the numerator) or cut burn by focusing spending on the highest-return activities (the denominator). The best operational lever depends on your current stage: early companies almost always benefit most from reducing churn, while growth-stage companies benefit from improving CAC efficiency and building expansion revenue.
SaaS Metric Benchmarks by Company Stage
| Metric | Seed | Series A | Series B | Growth/Scale | Target |
|---|---|---|---|---|---|
| Monthly Churn | 5-12% | 3-8% | 2-5% | 0.5-3% | < 2% |
| Annual Churn | 46-78% | 31-63% | 21-46% | 6-31% | < 10% |
| LTV:CAC Ratio | 2-3x | 3-4x | 3-5x | 4-6x | > 3x |
| CAC Payback (months) | 24-36 | 18-24 | 12-18 | 6-12 | < 18 |
| Net Revenue Retention | 80-95% | 90-105% | 100-115% | 110-130% | > 100% |
| Rule of 40 | N/A | 20-30% | 30-40% | 40%+ | > 40% |
| Gross Margin | 60-70% | 65-75% | 70-80% | 75-85% | > 70% |
| Magic Number | < 0.5 | 0.5-0.75 | 0.75-1.0 | > 1.0 | > 0.75 |
Industry benchmarks from OpenView Partners, KeyBanc Capital Markets, and Bessemer Venture Partners. Ranges reflect median top-quartile performance.
Frequently asked questions
What is the difference between MRR and ARR?
MRR (Monthly Recurring Revenue) is your predictable subscription revenue normalized to a single month. ARR (Annual Recurring Revenue) is MRR multiplied by 12. For companies with mostly monthly plans, MRR is the primary operational metric. For companies with mostly annual contracts, ARR is more commonly used because it reflects the committed contract value. Both exclude one-time fees, setup charges, and professional services revenue.
What is a good LTV:CAC ratio for a SaaS company?
The widely accepted benchmark is 3:1 or higher - you should earn at least $3 in lifetime value for every $1 spent acquiring a customer. Ratios below 1:1 mean you lose money on every customer. Ratios above 5:1 are considered outstanding, though very high ratios sometimes indicate you are underinvesting in growth. Seed-stage companies often operate at 2:1 while finding product-market fit, while growth-stage companies are typically expected to reach 4:1 or above.
How do I calculate Net Revenue Retention (NRR)?
NRR measures what percentage of revenue from your existing customer cohort you retain over a period, including upsells and cross-sells. The formula is: (Starting MRR + Expansion MRR - Churned MRR - Contraction MRR) / Starting MRR x 100. An NRR above 100% means existing customers are generating more revenue than you are losing to churn - sometimes called "negative churn". Best-in-class SaaS companies like Snowflake and Datadog have historically reported NRR above 130%.
What does the Rule of 40 actually measure?
The Rule of 40 measures whether a SaaS business is striking the right balance between growth and profitability. You add your annual revenue growth rate to your profit margin (using EBITDA, operating margin, or free cash flow margin - different investors use different definitions). A score above 40% is considered healthy. A company growing at 60% per year can burn at -20% margin and still clear the threshold. A mature company growing at 10% per year needs a 30% profit margin to clear it. It is most meaningful for companies with more than $10M ARR.
How long should my CAC payback period be?
Best-in-class SaaS companies recover their customer acquisition cost in under 12 months of gross margin. Under 18 months is considered healthy for most growth-stage businesses. Payback periods of 24 months or longer are a warning sign that either your CAC is too high or your ARPU and gross margin are too low to sustain efficient growth. Enterprise SaaS companies with large contracts and long sales cycles can operate with longer payback periods because the contracts are more predictable and sticky once signed.
What is the SaaS Magic Number and how is it interpreted?
The SaaS Magic Number measures go-to-market efficiency. It is calculated as the new ARR (adjusted for gross margin) generated in a period divided by the sales and marketing spend in the prior period. A magic number above 0.75 suggests your sales and marketing engine is working well and worth scaling. Above 1.0 is considered excellent. Below 0.5 signals that increasing sales and marketing spend will not produce proportional returns, and you may need to fix conversion rates, targeting, or pricing before scaling investment.
Why does monthly churn matter so much more than annual churn?
Monthly churn compounds. A 5% monthly churn rate is not 60% per year - it is closer to 46% per year because each month you are losing customers from an already smaller base. This means at 5% monthly churn, you replace nearly half your customer base every year purely from cancellations. At 2% monthly churn (roughly 22% annual), your average customer stays for about 50 months (over 4 years), giving them time to become profitable. At 5% monthly churn, the average tenure is only 20 months, dramatically compressing LTV.