MRR vs ARR: Which Should You Track?

• 1. Definitions
• 2. The math is the same, but the framing changes behavior
• 3. When to switch
• 4. The components of MRR (worth tracking every month, regardless)
• 5. Common mistakes when computing MRR/ARR
• 6. A worked example
• 7. Quick benchmarks to know
• Next steps

MRR (Monthly Recurring Revenue) and ARR (Annual Recurring Revenue) are the same number multiplied by 12. The reason both exist is purely cultural: small SaaS reports in MRR because the monthly delta is meaningful, large SaaS reports in ARR because the annual number sounds more impressive to the board and to investors. The right answer for your business depends mostly on size. Here is when to switch, why it matters, and how to project both with the MRR/ARR Projection Calculator.

The rule of thumb: Use MRR while it's still measured in thousands. Switch to ARR once you cross roughly $1M ARR.

1. Definitions

MRR = the normalized monthly recurring revenue from all active subscriptions, as of a specific date.

MRR = Σ (subscription value normalized to monthly)

A customer on a $1,200/year annual plan contributes $100/month to MRR. A customer on a $99/month plan contributes $99/month. Add them up across your customer base.

ARR = MRR × 12. That's literally it. ARR is just MRR expressed annually.

2. The math is the same, but the framing changes behavior

Both metrics compute the same underlying number, but reporting in MRR vs ARR subtly shifts how a team thinks:

Neither is right or wrong, but they imply different operating cadences.

3. When to switch

Most SaaS companies switch from MRR to ARR somewhere between $500K and $2M ARR. The trigger is usually one of:

• The board starts referring to numbers in ARR
• Annual contracts become >50% of new bookings
• The monthly delta becomes small relative to the total (< 2% MoM)
• You are raising a Series A and the deck conventions are ARR

There is no rule against tracking both internally forever — most companies do. But your public-facing single number gradually becomes ARR as you scale.

4. The components of MRR (worth tracking every month, regardless)

Whether you headline MRR or ARR, you must decompose the movement into its components every period:

The trajectory of each line tells you something specific about the health of the business — and a single aggregate MRR or ARR hides all of it.

5. Common mistakes when computing MRR/ARR

• Including one-time fees — implementation, training, setup. These are revenue, but not recurring. Keep separate.
• Including overage charges — usage-based overages are revenue but are not recurring at a predictable level. Separate.
• Counting contract bookings instead of activated revenue — a $120K annual contract signed today but starting next month is bookings, not ARR, until it activates.
• Including trials — trials are zero MRR until they convert to paid.
• Mis-handling discounts — MRR should be net of discount. A "$1,200/year" plan sold at a $200 discount contributes $1,000/12 = $83.33 to MRR.

6. A worked example

Last month you ended at $48,000 MRR. This month:

• 12 new customers averaging $150/mo each: +$1,800 New MRR
• 5 existing customers upgraded for a total of +$650: Expansion MRR
• 2 existing customers downgraded for −$200: Contraction MRR
• 3 customers cancelled for −$420: Churned MRR

Ending MRR = $48,000 + $1,800 + $650 − $200 − $420 = $49,830
Net New MRR = $1,800 + $650 − $200 − $420 = $1,830
ARR = $49,830 × 12 = $597,960

That's a 3.8% MoM growth, which annualizes to ~57% — solid for a sub-$1M company.

7. Quick benchmarks to know

• Healthy early-stage SMB SaaS grows MRR 10–20% MoM (200%+ ARR YoY)
• Healthy Series A grows 8–12% MoM
• Healthy Series B grows 5–8% MoM
• Public SaaS averages 25–40% ARR YoY

The numbers compound, so high MoM rates do not last forever. Going from 15% MoM to 5% MoM is not "decline" — it's normal scale.

Next steps

Two concrete actions:

1. Build a 12-month MRR/ARR projection in the MRR/ARR Projection Calculator, with realistic New, Expansion, and Churn assumptions.
2. Test sensitivity to churn — drop churn from 4% to 2% in the Churn Rate Calculator and re-run the projection. You will see why churn dominates ARR growth at scale.

Then decide: are you an MRR-team or an ARR-team this quarter? Pick one for external reporting and stay consistent for the next 4 quarters minimum.