SaaS Metrics Explained: MRR, ARR, Churn, LTV and CAC
SaaS metrics are the set of recurring-revenue KPIs — Monthly Recurring Revenue, Annual Recurring Revenue, churn rate, Customer Lifetime Value, Customer Acquisition Cost, and several efficiency measures — that subscription businesses use to track health, guide decisions, and communicate with investors. Understanding what each one measures, how it is calculated, and what a good number looks like is essential for anyone building, operating, or evaluating a software-as-a-service company.
Why SaaS metrics are different from traditional business metrics
A traditional product business books revenue when a sale closes. A SaaS business delivers software continuously under a subscription, so revenue arrives in small, recurring installments over months or years. That structure creates a fundamentally different financial reality: acquiring a customer today is expensive, but the value of that customer compounds over time as they renew, upgrade, and (ideally) expand their usage.
This is why SaaS companies track a different set of metrics than, say, a retailer. Revenue in any given month is not the most informative number — the trajectory of recurring revenue, the rate at which existing customers stay or leave, and the efficiency of turning marketing spend into lasting customer relationships matter far more. The metrics below capture all of those dimensions.
MRR and ARR: the revenue heartbeat
Monthly Recurring Revenue (MRR) is the normalized monthly revenue from all active subscriptions. It excludes one-time fees, professional services, and any non-recurring charges, which is what makes it useful: MRR is a clean, comparable number you can track from month to month to see exactly how the business is growing.
MRR is built from four moving parts:
- New MRR — revenue from customers who signed up this month
- Expansion MRR — additional revenue from existing customers who upgraded or added seats
- Contraction MRR — revenue lost from existing customers who downgraded
- Churned MRR — revenue lost from customers who cancelled entirely
Tracking all four components separately is important. A company where New MRR is masking high Churn MRR is in a very different position than one where the same ending MRR is driven by strong expansion from a stable customer base.
Annual Recurring Revenue (ARR) is simply MRR multiplied by 12. ARR is used for investor reporting, company valuations, and benchmarking against other SaaS companies, because it normalizes revenue to an annual view regardless of billing cycle. A company with $100,000 MRR has a $1.2M ARR.
Churn: the metric that determines whether growth is real
Churn is the rate at which a SaaS business loses customers or revenue. There are two versions, and both matter.
Customer churn rate measures the percentage of customers who cancelled in a period:
Example: 200 customers at the start of the month, 4 cancel → customer churn rate = 4 ÷ 200 = 2% per month
Revenue churn rate (also called MRR churn rate) measures the percentage of revenue lost from existing customers:
These two numbers often diverge, and when they do, it is revealing. If your largest accounts are churning while small accounts stick around, customer churn will look mild but revenue churn will look alarming. Tracking both prevents that blind spot.
A monthly revenue churn rate above 2% is a warning sign for most SaaS businesses. At 2% monthly, you lose roughly 22% of your revenue base each year just from cancellations — meaning you need to grow new revenue by more than 22% just to stay flat. For enterprise SaaS, monthly churn rates below 0.5% are achievable and expected.
NRR and GRR: the retention quality metrics
Net Revenue Retention (NRR), sometimes called Net Dollar Retention (NDR), is arguably the single most important metric for a mature SaaS business. It measures what percentage of your beginning MRR you retained from existing customers over a period, including both losses from churn and contraction and gains from expansion.
An NRR above 100% means your existing customers are generating more revenue this month than last month — even without acquiring a single new customer. This is the hallmark of a product with strong expansion motion.
Gross Revenue Retention (GRR) is the floor version of NRR — it shows what you retained excluding any expansion:
GRR can never exceed 100%. It isolates the stickiness of your core product from the contribution of your upsell motion. A GRR above 90% is strong; above 95% is elite for enterprise.
LTV and CAC: the unit economics pair
These two metrics exist as a pair. Neither means much without the other.
Customer Acquisition Cost (CAC) is the total cost to acquire one new customer. The standard calculation uses your sales and marketing spend divided by the number of new customers acquired in the same period:
Customer Lifetime Value (LTV) is the expected gross profit generated by a customer over their entire relationship with your company. The industry-standard formula for subscription businesses is:
Where ARPA is Average Revenue Per Account (MRR ÷ total customers). This formula assumes steady churn and constant ARPA — a simplification, but standard for early-stage modeling.
The ratio of the two — LTV:CAC — is the canonical SaaS unit economics benchmark. A ratio of 3:1 or higher is considered healthy: for every dollar you spend acquiring a customer, you expect to generate at least three dollars in gross profit. Below 1:1 means you are destroying value on every customer you acquire, no matter how fast you grow.
Worked example
Beginning MRR: $100,000 · Beginning customers: 200
S&M spend (month): $48,000 · New customers: 12
Churned MRR: $3,000 · Gross margin: 75%
ARPA = $100,000 ÷ 200 = $500/month
Revenue churn rate = $3,000 ÷ $100,000 = 3% per month
CAC = $48,000 ÷ 12 = $4,000
LTV = ($500 × 0.75) ÷ 0.03 = $375 ÷ 0.03 = $12,500
LTV:CAC = $12,500 ÷ $4,000 = 3.1× (healthy)
CAC Payback Period = $4,000 ÷ ($500 × 0.75) = $4,000 ÷ $375 = ~10.7 months
The CAC Payback Period — how many months it takes to recover your acquisition cost from gross profit — is a practical companion to LTV:CAC. A company might have a 5× LTV:CAC ratio but a 36-month payback period, meaning cash is tied up for three years before each customer turns cash-flow positive. For capital-constrained startups, shorter payback periods matter as much as high LTV:CAC ratios.
Rule of 40: balancing growth and profitability
The Rule of 40 is a single-number health check that adds your annual ARR growth rate to your profit or free cash flow margin:
A score of 40 or above is the benchmark for a healthy SaaS business. A company growing at 60% while losing 15% of revenue scores 45 — healthy. A company growing at 10% while profitable at 25% scores 35 — below the line but trending toward sustainability. A company growing at 10% while losing 20% of revenue scores −10 — neither growing fast nor becoming profitable, a dangerous position.
The Rule of 40 is popular with investors because it prevents optimizing for one dimension at the expense of the other. Very high-growth companies are forgiven for near-term losses because they are investing in future revenue. Slower-growth companies must compensate with profitability. A score above 60–70 is considered elite; below 20 is a red flag that demands attention to either the growth engine or the cost structure.
Burn Multiple: efficiency under pressure
Coined by investor David Sacks, the Burn Multiple measures how much cash a company burns for each dollar of net new ARR it generates:
Where Net New ARR = (Ending MRR − Beginning MRR) × 12. A Burn Multiple below 1× is excellent — you are generating more new ARR than you are burning. Above 2× is a warning; at scale, above 2× is typically a red flag for investors.
Burn Multiple is particularly useful because it scales with company size in a way that raw burn rate does not. A startup burning $200K/month while generating $400K in net new ARR (burn multiple: 0.5×) is far more efficient than one burning $200K while generating only $80K in net new ARR (burn multiple: 2.5×), even though their cash outflow is identical.
Quick reference: benchmark table
| Metric | Green (healthy) | Yellow (caution) | Red (action needed) |
|---|---|---|---|
| NRR | ≥ 100% | 90–100% | < 90% |
| GRR | ≥ 90% | 80–90% | < 80% |
| Monthly revenue churn | ≤ 1% | 1–2% | > 2% |
| LTV:CAC | ≥ 3× | 1–3× | < 1× |
| CAC Payback | < 12 months | 12–24 months | > 24 months |
| Rule of 40 | ≥ 40 | 20–40 | < 20 |
| Burn Multiple | ≤ 1× | 1–2× | > 2× |
| Runway | ≥ 18 months | 6–18 months | < 6 months |
How these metrics connect: reading the full picture
No SaaS metric tells the full story alone. The power is in reading them together:
- Strong NRR with weak new customer growth means the product is excellent but distribution is the bottleneck.
- Strong new customer growth with poor NRR (below 90%) means churn is silently erasing the work of your sales team. The leaky bucket problem.
- Excellent LTV:CAC with a 30-month payback means unit economics look great on paper but you will run out of cash before you realize them without continuous fundraising.
- A Rule of 40 score above 40 with a burn multiple above 3× means the efficiency score is being achieved through very slow growth — examine whether the company is starving itself of the investment it needs.
These tensions are by design. Taken together, the metrics force an honest view of whether a SaaS business is genuinely healthy — growing efficiently, retaining customers, and building lasting unit economics — or merely keeping up appearances in one dimension while trouble accumulates in another.
Calculate all your SaaS metrics in one place
Figro's free SaaS Metrics Calculator computes MRR, ARR, NRR, GRR, LTV:CAC, CAC Payback, Rule of 40, Burn Multiple, Quick Ratio, and Runway — with color-coded health scores — all in your browser. No signup, nothing uploaded.
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