AS | Ankit Sarawagi|Founder, CFOmatrix·July 2026·10 min read | Metrics |
- MRR is the building block, ARR is MRR times twelve. Both count only what recurs; strip out one-time fees, setup and services.
- ARR has three common definitions. Committed contract value (conservative), run-rate (trailing average annualised), and for usage a trailing-three-month average annualised.
- Usage pricing needs a smoothing method. A trailing-three-month average annualised is the honest way to state a run-rate that swings month to month.
- Consistency beats cleverness. The definition you pick matters less than applying it to every customer, every period, the same way.
- Bookings, billings and revenue are not ARR. Four different views of the same deal; confusing them misjudges growth and cash.
| 3 Common ways to define ARR | MRR × 12 The core ARR identity | 3 mo Trailing window for usage ARR |
| 1. What ARR and MRR actually mean 2. The three ways to define ARR 3. Calculating ARR under usage pricing | 4. The principle: consistency and restatement 5. Bookings vs billings vs revenue 6. FAQ |
What ARR and MRR Actually Mean
MRR is monthly recurring revenue: the predictable subscription revenue you earn in a single month from active customers, normalised to a monthly figure. ARR is annual recurring revenue: the same base expressed as a yearly number, which is simply MRR multiplied by twelve. Two rules make the number honest. First, count only what recurs: strip out one-time setup fees, implementation charges and professional services. Second, normalise the timing: an annual plan billed upfront still counts as one-twelfth of its value per month, because ARR and MRR measure the run-rate, not the cash you collected this month.
- Monthly and annual subscription fees
- Committed platform or seat fees
- Recurring usage that repeats every month
- Recurring add-on modules
- One-time setup or onboarding fees
- Implementation and professional services
- Hardware or pass-through charges
- Discounts and credits (net these off)
This is easy when a customer pays a fixed ₹1,00,000 a month for a fixed number of seats. It gets genuinely harder the moment revenue depends on how much the customer uses, which is the direction most modern SaaS, and nearly all AI SaaS, is moving. That is where a single “ARR” number needs a definition attached to it. For the wider metric set this sits inside, see the SaaS finance pillar guide and the companion post on SaaS unit economics.
The Three Ways Companies Define ARR
Ask three founders how they calculate ARR and you will often get three different methods. None of them is wrong, but they mean different things and they produce different numbers off the same customer base. Here are the three definitions in wide use.
The run-rate method is worth a worked example, because it is where founders most often disagree. Suppose a customer’s recurring revenue over the last three months was ₹10,000, then ₹20,000, then ₹30,000. The trailing-three-month average is ₹20,000. Annualise it and you report ₹2,40,000 of ARR for that customer.
| Step | Working | Amount |
| Month 1 | Recurring revenue earned | ₹10,000 |
| Month 2 | Recurring revenue earned | ₹20,000 |
| Month 3 | Recurring revenue earned | ₹30,000 |
| Trailing average | (10,000 + 20,000 + 30,000) ÷ 3 | ₹20,000 / mo |
| Run-rate ARR | ₹20,000 average × 12 | ₹2,40,000 |
Annualising only month 3 would report ₹3,60,000, fifty percent higher, off one good month that may not repeat. The trailing average is deliberately conservative: it makes ARR reflect a sustained run-rate rather than the best month you can find. That discipline is what makes the number believable to a board and an investor.
Calculating ARR Under Usage Pricing
Traditional SaaS is priced per seat, so a signed contract gives you a clean annual number. AI SaaS rarely works that way. Because the compute underneath is variable, pricing has migrated from per-seat toward consumption (per unit of usage) and, at the frontier, outcome-based (per resolved ticket, per qualified lead, per completed task). When the bill moves every month, there is no single contracted figure to call ARR, so the trailing-three-month-average-annualised method becomes the honest default.
In the AI SaaS companies I have worked with, a usage customer often has two very different numbers: the committed volume they signed for, and the actual consumption they are running at, which is frequently higher. Report committed ARR as the floor and run-rate ARR as the live picture, label each clearly, and never quietly swap one for the other between board decks.
A practical way to present it is to show both figures together, so the board sees the contractual floor and the current momentum at once.
Whatever billing model sits behind this, the metric must be computed the same way for everyone. To avoid the collection pain that usage billing can create, many teams pair it with an annual volume commitment or a prepaid wallet that usage draws down. Once you have a clean recurring base, ARR flows directly into net revenue retention, the metric that usually decides how the whole business is judged.
The Principle: Consistency, and Restate If You Change
Here is the part that matters more than the formula. The exact ARR definition you choose is far less important than defining it clearly, applying it to every customer and every period the same way, and, if you ever change it, restating history on the new basis so the trend stays comparable. A definition change is fine; an inconsistent series is not, because it manufactures growth or hides a decline that was really there all along.
Do not agonise over which ARR definition is “correct”. Choose the one that fits your pricing (trailing-three-month annualised if you are usage-priced), document it, and use it everywhere: board deck, data room, investor updates. A consistent, defensible number beats a flattering one every time.
Bookings vs Billings vs Revenue (and Where ARR Sits)
ARR and MRR are run-rate views. They are not the same as bookings, billings or recognised revenue, and confusing the four is how founders end up surprised by their cash position while “growing”. Take one annual deal and watch it show up as four different numbers.
| View | What it measures | This deal |
| Bookings | Total value the customer has committed to | ₹12,00,000 |
| Billings | What you have invoiced so far (upfront) | ₹12,00,000 |
| Revenue (month 1) | Earned and recognised over the service period | ₹1,00,000 |
| ARR / MRR | Recurring run-rate (annual / monthly) | ₹12,00,000 / ₹1,00,000 |
In short: bookings is the promise, billings is the invoice, revenue is what you have earned so far, and ARR/MRR is the recurring run-rate. For a usage customer these diverge even more, because there may be little or no committed booking at all, just consumption you bill and recognise as it happens. That is exactly why the collection design matters: annual commitments and prepaid wallets keep billings ahead of usage rather than chasing it in arrears. For how the unearned portion becomes a cash advantage, see the pillar section on deferred revenue in the SaaS finance guide.
“With usage pricing, ARR stops being a fact you read off a contract and becomes a method you have to declare. Declare it, apply it everywhere, and restate it if you change it. That is the whole discipline.”
Ankit Sarawagi, CFOmatrixFrequently Asked Questions
What is ARR?
ARR is annual recurring revenue: the normalised value of the recurring revenue you expect over a year from active subscriptions, expressed as an annual figure. It excludes one-time fees, professional services and other non-recurring income. ARR is simply MRR multiplied by twelve, but the important part is how you define the recurring base: committed contract value (conservative), run-rate (a trailing multi-month average annualised), or for usage pricing a trailing-three-month average annualised. The number matters less than defining a method and applying it consistently.
What is MRR?
MRR is monthly recurring revenue: the predictable subscription revenue you earn in a single month from active customers, normalised to a monthly figure. An annual plan billed upfront still counts as one-twelfth of its value per month, because MRR measures the recurring run-rate, not cash collected. MRR is the building block; ARR is MRR times twelve. Both should exclude one-time setup fees, services and other non-recurring revenue so the number reflects only what genuinely repeats.
How do I calculate ARR with usage-based pricing?
When revenue depends on how much a customer consumes, there is no single contracted annual number, so the honest method is a trailing-three-month average annualised: take the recurring usage revenue from the last three months, average it, and multiply by twelve. This smooths month-to-month volatility while reflecting the current run-rate. Some companies also report committed ARR (the minimum volume committed to) alongside this figure. Whichever you choose, define it in writing and apply it to every customer the same way.
Is committed ARR or run-rate ARR better?
Neither is universally better; they answer different questions. Committed ARR counts only the contractually locked amount, so it is conservative and defensible in diligence, but understates a usage business where customers consume above their commitment. Run-rate ARR (a trailing average annualised) captures actual momentum but can flatter a business during a spike. Many SaaS companies report committed ARR as the floor and run-rate as the live picture. Show both transparently and never quietly switch between them.
Can I change my ARR definition later?
Yes, but only if you restate history on the new basis so the trend stays comparable. Founders often start with a loose definition and tighten it as the business matures, which is fine. The unforgivable mistake is changing the method and leaving old periods on the old basis, which manufactures growth or hides a decline. If you move from run-rate to committed ARR, or change the trailing window, recompute every prior period the same way and note the change. Investors forgive a definition change; they do not forgive an inconsistent series.
What is the difference between bookings, billings and revenue?
Bookings is the total value a customer has committed to when they sign, including future years. Billings is what you have actually invoiced so far, which for an annual-upfront deal is the whole year on day one. Revenue is what you may recognise as earned, spread over the service period, so an annual plan is recognised one-twelfth per month. The three rarely equal each other in the same period, and ARR or MRR is a fourth, separate view of the recurring run-rate. Confusing them is how founders misjudge both growth and cash.
This is general educational information for founders, current to mid-2026, and not legal, tax or investment advice. ARR and MRR are management metrics, not defined accounting figures; recognised revenue follows the applicable accounting standard. Benchmarks and methods are indicative and vary by pricing model and stage. Verify the current position or consult a professional before acting on a specific matter.
| Net Revenue Retention and Churn SaaS Valuation and ARR Multiples | SaaS Unit Economics |
AS | Founder, CFOmatrix | Finance Strategy & Equity Compliance CFOmatrix is a knowledge platform focused on how finance actually works inside growing companies, from SaaS metrics and unit economics to structure, fundraising and exits. |