If you run a subscription business, you track MRR and ARR. But when investors ask "what's your revenue," which number do you give? And which one tells you whether your business is actually healthy?
This guide clarifies what each metric measures and when you should rely on each one for decision-making.
The Definitions
MRR (Monthly Recurring Revenue) is the predictable revenue from subscriptions that renew each month.
MRR = Sum of all active monthly subscription charges
ARR (Annual Recurring Revenue) is the annualized version—what MRR would be if every customer stayed for a full year at their current rate.
ARR = MRR × 12
Both measure recurring, predictable revenue. They don't include one-time fees, consulting, or irregular add-ons.
Why Both Matter
You might think: "Why not just use ARR? It's one number."
Because they serve different purposes:
- MRR shows momentum and month-to-month change. It's sensitive to seasonality, churn, and rapid growth.
- ARR shows scale and is what investors care about. It smooths out monthly noise.
Use both. Track MRR weekly or monthly for operations. Report ARR to investors and the board.
MRR: The Operational Metric
Track MRR when you're managing the business day-to-day.
What MRR tells you:
- Whether this month is growing or declining versus last month
- Whether churn is accelerating or improving
- Whether a new sales push is working (appears in MRR within weeks)
- How much runway you have (cash on hand ÷ monthly burn)
Why MRR is more honest for early-stage: An early-stage SaaS company might have:
- MRR: $15,000
- ARR: $180,000
The MRR is the reality of what you're generating right now. The ARR assumes every customer stays for a year (they won't). MRR is the number that matters for survival.
Real example:
- January MRR: $50,000
- February MRR: $48,000 (churn hit)
- March MRR: $52,000 (new sales recovered it)
You see momentum play out month-to-month. ARR would just average it out and hide the problem.
Calculating MRR: The Methods
Method 1: Direct Sum Add up all recurring charges for active subscriptions this month.
MRR = Customer A subscription + Customer B subscription + Customer C subscription...
Method 2: Cohort-Based Segment MRR by month of acquisition (easier to track churn).
MRR = Sum of all subscription values from cohort 1 + cohort 2 + ...
Method 3: From Revenue per Seat For per-user pricing:
MRR = Average subscription value × Active subscribers
Most SaaS companies use a combo: track it directly from billing systems + break it down by cohort so you can see which customers are churning.
ARR: The Scale Metric
Report ARR when talking to investors, board members, and for long-term planning.
What ARR tells you:
- The annual value of your subscription base (annualized)
- How you compare to industry benchmarks
- Whether you're on track to hit growth targets
- Your "size" as a company (ARR is how investors compare you to peers)
Real example: A company with $200,000 MRR has:
ARR = $200,000 × 12 = $2,400,000 annual revenue run rate
Investors think: "This is a $2.4M ARR company." That's the language of scale.
But here's the caveat: This assumes zero churn. In reality, some customers will churn this year, so actual revenue might be $2.2M. That's why:
Net Revenue Retention ARR = ARR × (1 - Churn Rate) + Expansion Revenue
This is the more honest ARR number, and it's what investors actually want to see.
The "Growth vs. Reality" Problem
This is where tracking both matters most.
Company A
- MRR: $100,000 → $120,000 (20% growth, strong)
- ARR: $1.2M → $1.44M
Company B
- MRR: $500,000 → $550,000 (10% growth, slower)
- ARR: $6M → $6.6M
Who's in better shape? Depends. Company A has stronger month-to-month momentum, but Company B has more scale. Both metrics are important.
Without MRR, you might miss that Company A's growth is accelerating. You'd only see "both companies grew."
Without ARR, investors would say Company A's $1.44M scale is too small to be interesting.
How They Change Over Time
Here's a typical growth trajectory:
| Month | MRR | ARR | Change | |-------|-----|-----|--------| | Jan | $50,000 | $600,000 | +15% MoM | | Feb | $52,000 | $624,000 | +4% MoM | | Mar | $56,000 | $672,000 | +7% MoM | | Apr | $58,000 | $696,000 | +3% MoM | | May | $61,000 | $732,000 | +5% MoM | | Jun | $63,000 | $756,000 | +3% MoM |
Notice: MRR shows month-to-month variability (churn one month, strong sales the next). ARR smooths this out into a steady climb. Both tell a growth story, but MRR shows execution, while ARR shows scale.
Seasonality and the MRR vs. ARR Gap
Seasons matter for some businesses.
Example: HR Software
- January MRR: $150,000 (year-end budgets, hiring)
- July MRR: $100,000 (summer hiring slowdown)
- ARR (Jan): $1.8M
- ARR (July): $1.2M (but this overstates July's real value)
If you only look at ARR, you miss the seasonal dip. If you only track MRR, you might panic in July and cut spending, missing the cyclical recovery in January.
Better approach: Track both, and understand seasonality in your business.
Quick Comparison Table
| Aspect | MRR | ARR | |--------|-----|-----| | Calculated as | Sum of monthly subscriptions | MRR × 12 | | What it measures | This month's revenue | Annualized revenue run rate | | Update frequency | Weekly or monthly | Quarterly or annually | | Who cares | Operations, product, sales leadership | Board, investors, finance | | Shows | Momentum, week-to-week health | Scale, year-over-year benchmarking | | Sensitive to | Churn, new sales, seasonality | Long-term trends | | Reality check | How much revenue right now | How much revenue if nothing changes |
When to Use Each
Use MRR when:
- Tracking week-to-week or month-to-month performance
- Analyzing cohort retention and churn
- Managing cash flow and runway
- Evaluating a sales campaign's impact
- Adjusting budget or hiring decisions
Use ARR when:
- Reporting to board or investors
- Comparing to industry benchmarks
- Planning annual budgets
- Making multi-year strategic decisions
- Assessing company "size" and valuation
The Golden Rule
Report both, but manage by MRR.
Your operations team lives in MRR land (month-to-month reality). Your investors live in ARR land (annualized scale). By tracking both, you're optimizing for the health of the business (MRR) while also tracking your path to scale (ARR).
If your MRR is growing 3% month-over-month, your ARR is growing too. But if your MRR is flat and your ARR looks good, you have a churn problem hiding in the monthly data.
Pay attention to both.