SaaS growth metrics are the quantitative indicators that reveal whether a software business is growing sustainably or is headed toward stagnation or contraction. Unlike metrics for traditional businesses, SaaS growth metrics are designed to capture the dynamics specific to recurring revenue: the compounding effect of retention, the drag of churn, the economics of customer acquisition, and the leverage of expansion revenue from existing customers.
Understanding which SaaS growth metrics matter most — and how they relate to each other — is essential for founders, executives, and investors evaluating whether a business is on a healthy growth trajectory.
The Core SaaS Revenue Metrics
Monthly Recurring Revenue (MRR) and Annual Recurring Revenue (ARR)
MRR is the normalized monthly revenue from all active subscriptions. ARR is MRR multiplied by 12. These are the foundational metrics of a SaaS business — the consistent, predictable revenue base that makes SaaS businesses valuable relative to transaction-based models. MRR growth rate (month-over-month percentage change) is the most basic measure of how fast the business is growing at the revenue level.
MRR can be decomposed into four components: new MRR (revenue from new customers acquired in the period), expansion MRR (incremental revenue from existing customers upgrading or buying more), contraction MRR (revenue lost from existing customers downgrading), and churned MRR (revenue lost from customers who cancelled). Net new MRR = new + expansion – contraction – churned. A business where expansion MRR consistently exceeds churned + contraction MRR has a compounding revenue engine that makes growth easier over time.
Net Revenue Retention (NRR)
Net revenue retention (also called Net Dollar Retention or NDR) measures how much revenue a cohort of existing customers generates over time relative to the revenue they generated at the start of a period. The formula: (Beginning MRR + expansion MRR – contraction MRR – churned MRR) / Beginning MRR.
NRR above 100% means your existing customer base is growing revenue without adding any new customers. This is one of the most powerful dynamics in SaaS: a company with 110% NRR will grow revenue even if it stops acquiring new customers entirely, because expansion from existing customers more than offsets churn. Best-in-class SaaS companies (Snowflake, Datadog, HubSpot at peak) have NRR of 120-130% or higher. Median SaaS NRR is approximately 100-105%. NRR below 90% indicates a severe retention problem that new customer acquisition cannot sustainably offset.
Gross Revenue Retention (GRR)
Gross revenue retention measures retention without the benefit of expansion. It is capped at 100% and reflects what percentage of beginning-period revenue is retained after accounting for churn and contraction, excluding any upsell or expansion. GRR provides a cleaner view of customer retention than NRR because expansion revenue can mask poor base retention. A company with 70% GRR and 115% NRR is churning customers rapidly but offsetting it with aggressive upsells to the customers who stay — a potentially fragile position.
Customer Acquisition Metrics
Customer Acquisition Cost (CAC)
CAC is the fully-loaded cost of acquiring a new customer: total sales and marketing spend divided by the number of new customers acquired in the same period. CAC should include salaries, benefits, software, agency fees, advertising spend, and any other costs attributable to the customer acquisition function. Companies that calculate CAC using only advertising spend dramatically understate the true cost of acquisition and overstate the economics of their growth model.
LTV:CAC Ratio
The LTV:CAC ratio compares the lifetime value of a customer to the cost of acquiring them. LTV is typically calculated as ARPA (average revenue per account) multiplied by gross margin divided by the churn rate. An LTV:CAC ratio above 3:1 is generally considered healthy for B2B SaaS — meaning the lifetime revenue from a customer is at least 3x the cost of acquiring them. Ratios below 1:1 indicate the business is losing money on each customer acquired. Ratios above 5:1 may indicate the business is underinvesting in growth (leaving addressable market to competitors by being too conservative on CAC).
CAC Payback Period
CAC payback period is the number of months required to recover the cost of acquiring a customer through their gross margin contribution. The formula: CAC / (ARPA x Gross Margin). A 12-month payback period means the business recovers its customer acquisition cost in one year. Payback periods below 12 months are generally strong for venture-backed SaaS. Above 24 months creates significant cash flow pressure because the business must fund a long period of “negative” per-customer economics before each new customer reaches profitability.
Churn and Retention Metrics
Customer Churn Rate
Customer churn rate is the percentage of customers that cancel in a given period. Monthly churn rates of 2-3% or less are common for SMB-focused SaaS. Enterprise-focused SaaS should target monthly churn below 0.5-1%. Annual churn rates above 15% for most B2B SaaS segments indicate a retention problem that compounds quickly: a business with 15% annual churn loses half its customer base every four years and must replace it entirely through new acquisition just to maintain flat revenue.
Revenue Churn Rate
Revenue churn rate measures the percentage of revenue lost to cancellations and downgrades in a period. It is distinct from customer churn rate: a business serving both SMB and enterprise customers might lose 10 SMB customers (high customer churn) but only a small percentage of revenue if those customers each paid a fraction of what enterprise accounts pay. Revenue churn rate is the more business-critical metric for evaluating the health of retention.
Growth Efficiency Metrics
The Rule of 40
The Rule of 40 is a heuristic for evaluating whether a SaaS company is balancing growth and profitability appropriately. The formula: revenue growth rate (%) + profit margin (%) should equal or exceed 40. A company growing at 50% with a -10% profit margin scores 40 — on the boundary. A company growing at 20% with 15% margins scores 35 — below benchmark. The Rule of 40 recognizes that fast growth and high margins are both valuable, and the two can be traded off against each other, but the combined score should not fall too far below 40 for the business to be considered healthy at the portfolio level.
Magic Number
The Magic Number measures sales efficiency: how much incremental ARR is being generated per dollar of sales and marketing spend. The formula: (Current Quarter ARR – Prior Quarter ARR) x 4 / Prior Quarter Sales and Marketing Spend. A Magic Number above 1.0 indicates the business is generating more than $1 of annualized revenue for each $1 of sales and marketing spend — generally considered a signal to invest aggressively in growth. Below 0.75 suggests the growth engine is not efficient enough to justify scaling spend.
Burn Multiple
Burn multiple measures how much cash a company burns to generate each dollar of net new ARR. The formula: Net Cash Burned / Net New ARR. A burn multiple below 1x is outstanding (growing faster than you are burning). 1-1.5x is good. Above 2x warrants scrutiny, and above 3x suggests the business may be spending significantly more than the growth it is generating justifies. Burn multiple became a primary investor metric during the capital-efficiency correction of 2022-2023 when the market shifted emphasis from growth rate to growth quality.
Product and Adoption Metrics
Daily Active Users / Monthly Active Users (DAU/MAU)
The DAU/MAU ratio measures how sticky the product is: what fraction of monthly active users engage with the product every day. A ratio above 20% is generally considered good stickiness for most SaaS products. Consumer apps with high social or utility features (Slack, Figma, communication tools) often reach 50%+. The relevance of DAU/MAU as a metric depends on the product: a tool used daily by nature (messaging, project management) should have high DAU/MAU. A tool used weekly or monthly by nature (board reporting, annual planning) should not be measured against daily engagement benchmarks.
Time to Value (TTV)
Time to value is the duration between a customer signing up and their first meaningful experience of the product’s core value. In product-led growth products, TTV is measured in minutes or hours (the time from signup to the first “aha moment”). In complex enterprise implementations, TTV may be measured in weeks. Reducing TTV reduces early-stage churn (customers who leave before experiencing value) and accelerates the moment when customers become advocates who refer others. TTV optimization is often the highest-leverage product investment for early-stage SaaS companies.
Understanding and improving these SaaS growth metrics is not the end goal — the goal is building a business where they compound favorably over time. NRR above 100%, CAC payback shortening, churn declining as the customer base matures, and margins expanding as the organization scales are the indicators of a SaaS business that will continue to grow in value regardless of the macroeconomic environment.