MRR/ARR Growth Rate Calculator

Enter three numbers. Starting MRR and Ending MRR should be measured the same way, normally the recurring revenue on the last day of each month, excluding one-off setup fees and usage overages you do not expect to recur. Months between them is the gap between the two measurements, from 1 to 60, not the number of monthly data points: January 31 to July 31 is 6 months.

With $50,000, $65,000 and 6, the headline MRR growth rate is 30.00%. Below it, CMGR is 4.47% and net new MRR is $15,000, the absolute dollars added after all new business, expansion, contraction and churn.

The run-rate block shows current ARR of $780,000 ($65,000 × 12), then a 12-month projected MRR of $109,850 and projected ARR of $1,318,200. The projection simply compounds the ending MRR at the CMGR for 12 more months: $65,000 × 1.0447^12. The chart places starting, ending and projected MRR side by side, which makes the size of that assumption visible.

Use CMGR, not the period growth rate, when comparing periods of different length. A 30% half-year and a 20% quarter sound similar, but their CMGRs are 4.47% and 6.27% respectively, so the quarter was growing faster.

Negative inputs are treated as zero and the month count is at least 1. With S = starting MRR, E = ending MRR and m = months:

• Net New MRR = E − S
• MRR Growth Rate = (E − S) ÷ S × 100, reported as 0 when S is 0
• CMGR = ((E ÷ S)^(1 ÷ m) − 1) × 100, reported as 0 when either S or E is 0
• ARR = E × 12
• 12-Month Projected MRR = E × (1 + CMGR ÷ 100)^12
• 12-Month Projected ARR = Projected MRR × 12

CMGR is a geometric mean. Raising the total growth multiple, E ÷ S, to the power 1 ÷ m finds the single monthly multiplier that, applied m times, turns S into E exactly. For the example, 1.3^(1/6) = 1.0447, and 1.0447 compounded six times returns $65,000. Dividing the total rate by the number of months ignores compounding and overstates the monthly rate: 5% a month for six months would grow $50,000 to $67,005, not $65,000.

ARR here is a run rate: this month's recurring revenue annualised. It is not the revenue collected over the last 12 months, which for a growing company is lower.

Enter $20,000 starting MRR, $40,000 ending MRR and 12 months. The period growth rate is 100.00%, net new MRR is $20,000, and CMGR is 5.95% a month, well below the 8.33% you would get from 100 ÷ 12. Current ARR is $480,000.

The projection shows how quickly compounding escalates. Another year at 5.95% a month doubles MRR again, to $80,000, for a projected ARR of $960,000. The net new MRR in that projected year would be $40,000, twice this year's $20,000, from the same percentage rate. The reverse is also true: holding a constant percentage requires ever-larger absolute gains, which is why growth rates usually slow as revenue grows.

Doubling in a year matches the "double" years of the T2D3 path that Neeraj Agrawal of Battery Ventures described in TechCrunch in 2015: after reaching about $2 million ARR, triple ARR in each of the next two years, then double it in each of the three after that, reaching $144 million. On this calculator, a tripling year is a CMGR of 9.59% and a doubling year is 5.95%. For very early companies, Paul Graham's 2012 essay "Startup = Growth" called 5-7% a week a good rate during Y Combinator, a far steeper bar that applies to tiny revenue bases over a few months, not to established SaaS businesses.

Many dashboards report "average monthly growth" by adding up each month's growth rate and dividing by the number of months. That arithmetic mean is always greater than or equal to CMGR, and equal only when every month grew at exactly the same rate. The more volatile the months, the bigger the overstatement.

Take MRR that moves from $100,000 to $130,000 to $104,000 to $135,200 over three months. The month-over-month rates are +30%, −20% and +30%, and their simple average is 13.33%. Compounding 13.33% for three months from $100,000 gives $145,570. The company actually ended at $135,200. Enter $100,000, $135,200 and 3 months into the calculator and it returns the true figures: 35.20% total growth and a CMGR of 10.58%.

The reason is that percentages are taken from different bases. The 20% drop was taken from $130,000, so it removed $26,000, while the 30% recovery was taken from the smaller $104,000 and added back only $31,200. Averaging those two months says they grew 5% a month, about 10% in total, when a +30% month followed by a −20% month is actually a 4% gain in total (1.30 × 0.80 = 1.04). Use CMGR for anything that will be compounded, projected or compared against another company.

The calculator only sees two points. It cannot tell a steady climb from a volatile path with the same start and end, and a single large contract landing in the final month can make a slow period look fast. It also cannot separate new MRR, expansion, contraction and churn; a flat net figure might hide heavy churn offset by strong sales.

The 12-month projection assumes the CMGR continues unchanged, which is rarely true. Short, volatile windows produce extreme results: the three-month $100,000 to $135,200 example above projects $451,735 MRR a year later. Treat projections from fewer than about six months of data with particular caution.

Edge cases: when starting MRR is 0, growth rate and CMGR both show 0 because a percentage change from zero is undefined. When ending MRR is 0, CMGR also shows 0 even though revenue fell 100%, so read the growth rate and net new MRR in that case. ARR as MRR × 12 does not account for annual contracts billed up front, seasonal businesses or revenue recognition rules, and it is not a substitute for audited revenue figures.

Growth is only valuable if the customers behind it are profitable. The Customer Lifetime Value Calculator estimates what a customer is worth over their lifespan, and the CLV to CAC Ratio Calculator compares that value with what it cost to acquire them, a check that fast MRR growth is not simply bought at a loss. To see the per-user revenue behind an MRR figure, the ARPU, ARPA & ARPPU Calculator splits revenue across active and paying users. If growth is funded by cash in the bank, the SaaS Burn Rate & Runway Calculator shows how long that growth can be sustained.