About the MRR/ARR Calculator
This calculator estimates a subscription business's Monthly and Annual Recurring Revenue from customer count and average price, and separately tracks net new MRR added during the current month. It is built for SaaS and subscription operators who want a fast top-line revenue snapshot without pulling numbers from a billing system.
How It Works
You enter the number of paying customers and the average monthly price per customer; the tool multiplies these to get MRR, then multiplies MRR by 12 to get ARR. Separately, you can optionally enter New MRR added this month and Churned MRR lost this month, and the calculator subtracts churned from new to show Net New MRR for the month.
Formula & Methodology
Start with your total count of active paying customers and multiply by the average amount each pays per month to get MRR. That figure represents recurring revenue normalized to a monthly cadence, even if some customers are on annual contracts (their annual price would need to be divided by 12 before averaging in). Multiply MRR by 12 to annualize it into ARR. The Net New MRR figure is calculated independently of the customer-count MRR: it simply nets the dollar amount of MRR gained from new sign-ups against the dollar amount lost to cancellations in the same month, giving a separate read on momentum.
Examples
Mid-size subscription business
150 customers paying an average of $49/month gives MRR = 150 x $49 = $7,350, and ARR = $7,350 x 12 = $88,200. If $800 in new MRR was added and $300 in MRR churned that month, Net New MRR = $800 - $300 = $500.
Smaller early-stage business
40 customers at an average of $25/month gives MRR = 40 x $25 = $1,000, and ARR = $1,000 x 12 = $12,000. With $200 in new MRR and $150 in churned MRR, Net New MRR comes to $50 for the month.
Advantages
- Converts a customer count and price point into both a monthly and an annualized revenue figure in one step, useful for quick investor or internal reporting
- Separates the underlying revenue base (MRR/ARR) from the month's momentum (Net New MRR), giving two distinct signals from one form
- Requires only inputs that most subscription businesses already track, without needing to export data from a billing platform
Common Mistakes
- Entering an average monthly price that hasn't been normalized for annual-plan customers, which inflates the MRR and ARR totals
- Treating ARR as a guaranteed annual figure rather than a run-rate snapshot that assumes the current MRR holds steady for 12 months
- Forgetting to update New MRR and Churned MRR each month, which leaves Net New MRR stuck at zero or stale
Edge Cases to Watch For
- The MRR and ARR figures come purely from customers x average price, so if your customer base includes a mix of monthly and annual billing, you need to normalize annual prices to their monthly equivalent before entering the average, or the MRR figure will overstate revenue.
- New MRR and Churned MRR are optional inputs; if left at zero, Net New MRR will simply show as zero minus zero rather than reflecting actual month-over-month movement.
- The calculator does not validate that customer count or average price are positive, so entering zero customers will correctly show $0 MRR and $0 ARR rather than an error.
- Averaging price across a customer base with very different plan tiers can mask meaningful segments; a single blended average may not represent what any individual customer actually pays.
Common Use Cases
- SaaS founders preparing a quick investor update or board summary without exporting a full billing report
- Finance teams cross-checking a billing system's reported MRR against a simple customers-times-price estimate
- Early-stage subscription businesses that don't yet have automated MRR tracking and are calculating it manually