SaaS Metrics Calculator
Build the MRR bridge and read every SaaS metric from one month-by-month table.
MRR movements and net new MRR
- New
- Expansion
- Reactivation
- Contraction
- Churn
- Net new MRR
Positive movements stack above the zero line, negative ones below; the line is each month’s net new MRR. Hover or tap a month for its full figures.
MRR bridge and retention, month by month
How this was calculated
Sources: Brad Feld on the Rule of 40%, David Sacks on the Burn Multiple, and Mamoon Hamid’s SaaS quick ratio.
Month 1
Results are estimates for general information and planning, not financial advice. Banks and institutions may calculate differently (rounding, fees, rate changes). Confirm figures with your lender or a qualified adviser before deciding.
About the SaaS Metrics Calculator
The month-by-month MRR bridge is the one table every SaaS metric comes from: opening MRR + new + expansion + reactivation − contraction − churn = closing MRR. Enter up to 36 months of these movements and the calculator gives ARR, net new MRR, month-on-month and compound growth, net and gross revenue retention (monthly and annual), ARPA, the SaaS quick ratio (Mamoon Hamid), the Rule of 40 (Brad Feld) and the burn multiple (David Sacks), with a column chart of the movements and a running line of net new MRR.
Everything is worked out in your browser. Paste a sheet from your subscription tool, type one month at a time, or load the sample year and change the figures. The result is a readable dashboard you can share: no sign-up, no upload, no tracker.
How to use it
- Enter the opening MRR at the start of the first month (0 for a new product), and optionally pick the first month so the chart and labels have names.
- For every month, enter the MRR movements: new, expansion, contraction, churn and (if any) reactivation. Add customers at the end of the month for ARPA, and net burn for the burn multiple.
- Optional: enter the profit margin (EBITDA or free-cash-flow margin) in percent to score the Rule of 40.
- Paste from a spreadsheet or an export under Paste a sheet (New MRR, Expansion, Contraction, Churn, Reactivation, Customers, Net burn — any order with a header, or in that order without one).
- Read the headline figures, the chart and the month-by-month table, then Copy summary or Download CSV.
Examples
Opening 100,000 · 12 months of rising new MRR (8–12.4k), expansion (2–3.1k), churn (1.8–2.35k), occasional reactivation, net burn falling from 150k to 128k, profit margin −85%
Closing MRR 221,580 · ARR 2,658,960 · year-on-year growth 121.58% Annual NRR 97.85% · annual GRR 79.34% SaaS quick ratio 4.64 Rule of 40 = 121.58% − 85% = 36.58% (does not pass) Burn multiple = 1,668,000 ÷ 1,458,960 = 1.14× (great) · last 3 months 0.90× (amazing)
Opening 100,000 · expansion 2,000 · contraction 600 · churn 1,800 · reactivation 500
(100,000 + 2,000 − 600 − 1,800) ÷ 100,000 = **99.6% NRR** GRR = (100,000 − 600 − 1,800) ÷ 100,000 = 97.6%
Reactivation (customers who had cancelled and come back) is treated as new revenue in the bridge, so it is not in the NRR numerator for the same reason new MRR is not.
Net burn 2.0M in a quarter · net new MRR 83k in the same quarter (net new ARR 996k)
Burn multiple = 2.0M ÷ 996k ≈ 2.01× (suspect)
A burn multiple above 3× is “bad” and under 1× “amazing” on David Sacks’ scale.
Growth 20% · EBITDA margin 20%
20 + 20 = 40 → passes
Feld: “Just do year-over-year growth rate of monthly MRR … I prefer to use EBITDA … as the baseline.” He adds that the rule is for SaaS at scale — “assume at least $50 million in revenue”.
Common uses
- Report monthly SaaS metrics to a board or an investor without a dashboard tool.
- Set a growth and retention goal: compound monthly figures that would hit the target for the year.
- Compare the quick ratio and burn multiple of two product lines or two years, side by side.
- Score the Rule of 40 at different growth and margin trade-offs before planning the year.
The MRR bridge
Normalise every subscription to one month (an annual plan of $1,200 is $100 of MRR, a 15-month plan at $150 a month is $150 of MRR for 15 months), classify each movement and the arithmetic falls out:
- New MRR: added by customers who had no MRR at the start of the month.
- Expansion MRR: added by existing customers that stayed (upgrades, more seats, more usage).
- Reactivation MRR: brought back by customers who had cancelled before this month (also called resurrected or win-back MRR).
- Contraction MRR: lost by customers that stayed, as downgrades or lower usage.
- Churned MRR: lost by customers that fully cancelled during the month.
Closing MRR = Opening + New + Expansion + Reactivation − Contraction − Churn and Net new MRR = New + Expansion + Reactivation − Contraction − Churn. Multiply closing MRR by 12 for ARR.
Retention: NRR and GRR, monthly and annual
From the movements:
Monthly NRR = (Opening + Expansion − Contraction − Churn) ÷ Opening MRR— the retained value of the customers you had at the start.Monthly GRR = (Opening − Contraction − Churn) ÷ Opening MRR— the same, without expansion.
Reactivated revenue is not in NRR or GRR (those customers were not customers at the start of the month). The annual figures compound the monthly rates over the last 12 months, so a monthly GRR of 98.09% ≈ 79.34% a year. A true cohort NRR follows exactly the customers you had a year ago; movements include customers who joined during the year, so this is an approximation. It still travels in the right direction and is the figure most SaaS dashboards show.
The SaaS quick ratio, the Rule of 40 and the burn multiple
Three sanity checks SaaS investors read first:
- SaaS quick ratio (Mamoon Hamid):
(New + Expansion + Reactivation) ÷ (Contraction + Churn). 1 is break-even; 4 was Hamid’s rule of thumb for healthy growth. - Rule of 40 (Brad Feld): revenue growth % + profit margin % ≥ 40. Feld suggests year-on-year growth of monthly MRR for the growth half and EBITDA for the profit half. Meant for SaaS at scale — Feld says “at least $50 million in revenue.”
- Burn multiple (David Sacks):
Net burn ÷ Net new ARR. Sacks’ rules of thumb for venture-stage startups: under 1× amazing, 1–1.5× great, 1.5–2× good, 2–3× suspect, over 3× bad. Pre-revenue the ratio does not even compute.
Sources: Brad Feld on the Rule of 40% and David Sacks on the Burn Multiple. The quick ratio is Mamoon Hamid’s, from a SaaStr talk that has been reproduced many times since.
ARPA, CMGR and year-on-year
- ARPA = closing MRR ÷ paying customers at the end of the last month.
- CMGR (compound monthly growth rate) over N months = (Closing MRR ÷ Opening MRR)^(1 ÷ N) − 1. Shown when both are above zero.
- Year-on-year growth: when 12 months or more are entered, closing MRR against the MRR 12 months earlier; otherwise the CMGR compounded for 12 months, which the result labels “annualised.”
Limitations
- MRR is monthly recurring revenue only: one-off set-up fees, services and usage overages are not SaaS MRR and should be left out, or shown separately.
- The annual retention is a compounded monthly figure, not a cohort NRR; it moves in the same direction but will differ from a cohort calculation when customers who join during the year are a large share of revenue.
- The burn multiple needs net burn in the same months as the MRR movements, and does not compute when ARR shrank over the period (negative net new ARR).
- Rule of 40 benchmarks were defined for SaaS at scale; readings on a very small base are not comparable.
- A guide to the metrics, not investment advice: how to run the business is a decision for its owners and board.
Privacy
Everything is worked out in your browser. The movements, customers and burn you enter are never uploaded.
Frequently asked questions
How is net revenue retention calculated?
(Opening MRR + Expansion − Contraction − Churn) ÷ Opening MRR for the month, then compounded over up to 12 months for the annual rate. Reactivated customers (who had cancelled before the month) are new revenue, so they are not in the numerator — just as new MRR is not.
What is a good SaaS quick ratio?
Mamoon Hamid’s rule of thumb was 4: four units of new, expansion and reactivation for every unit of contraction and churn. Any ratio above 1 means revenue grew, but 4 is the figure venture investors look for.
How is the burn multiple classified?
By David Sacks’ scale for venture-stage startups: under 1× amazing, 1–1.5× great, 1.5–2× good, 2–3× suspect, over 3× bad. The calculator applies these cut-offs and shows the burn, the net new ARR and the ratio for both the full period and the last 3 months.
Does the Rule of 40 use revenue or MRR growth?
Brad Feld prefers year-on-year growth of monthly MRR, which this calculator uses. For periods under 12 months the growth is the CMGR annualised and the result says so, so you know the figure is a projection.
Why does the quick ratio sometimes show ∞ for a month?
A month with no contraction and no churn divides by zero. The calculator shows ∞ for that month and leaves it out of the period quick ratio only when nothing was ever lost over the whole period.