People search for a churn rate calculator when a subscription list gets smaller and they want the share that left.
Customer churn is customers lost divided by customers at the start of the period. Revenue churn is churned recurring revenue divided by starting monthly recurring revenue. The customer churn calculator uses both:
Customer churn = customers lost ÷ starting customers
Revenue churn = churned MRR ÷ starting MRR
Ending customers = starting − lost + new
The SBA’s manage-your-business guide treats customers, revenue, and cash as figures you track on a period you choose. Keep every input on that same month, quarter, or year. New customers change the ending count. They do not enter the churn rate.
These are labeled examples from that formula. They are not a forecast, and they are not business advice.
Fig 1
Two rates, one period
New customers stay out of both rates
Customer churn uses the opening headcount. Revenue churn uses starting MRR. Ending customers add the new accounts after the loss.
Customer churn and revenue churn
Read the customer rate first. Then read the revenue rate. They match when the accounts that left were about the same size as the average account. They split when a few large accounts leave, or when the lost accounts were smaller than average.
People also search this customer-count rate as logo churn. On this page it is the same ratio: lost customers ÷ starting customers.
The revenue line here is the share of starting MRR that left. Expansion and new MRR are not in that ratio. A page that keeps expansion inside the starting cohort is the net revenue retention calculator. Lifetime value of the accounts that stay is the LTV:CAC calculator.
Example 1: the calculator defaults
Inputs:
- customers at the start: 250
- customers lost: 15
- new customers: 22
- starting MRR: $30,000
- churned MRR: $1,800
Customer churn: 15 ÷ 250 = 0.06 = 6%
Revenue churn: 1,800 ÷ 30,000 = 0.06 = 6%
Ending customers: 250 − 15 + 22 = 257
Net customer change: 22 − 15 = +7
Calculator result
Customer churn rate
- Customers at the start
- 250 customers
- Customers lost
- 15 customers
- New customers
- 22 customers
- Starting monthly recurring revenue
- $30,000.00
- Churned MRR
- $1,800.00
6%
customer churn rate
- Revenue churn rate
- 6%
- Ending customers
- 257
- Net customer change
- 7
Average starting MRR per customer is 30,000 ÷ 250 = $120. Average churned MRR per lost customer is 1,800 ÷ 15 = $120. The two rates match because the lost accounts were the same size as the average account.
Of the 250 at the start, 235 stayed. That is 235 ÷ 250 = 94%. The 15 who left are the other 6%.
Fig 2 · 1/2
Where the opening 250 went
Defaults. 15 lost, 22 new, $30,000 starting MRR.
Stayed
235
Lost
15
235 customers stayed. That is 94% of the opening count.
15 customers left. That is the 6% customer churn rate.
Example 2: a studio with 40 customers
Inputs: start 40, lost 3, new 1, starting MRR $8,000, churned MRR $900.
Customer churn: 3 ÷ 40 = 0.075 = 7.5%
Revenue churn: 900 ÷ 8,000 = 0.1125, which the page rounds to 11.3%
Ending customers: 40 − 3 + 1 = 38
Net change: 1 − 3 = −2
Calculator result
Customer churn rate
- Customers at the start
- 40 customers
- Customers lost
- 3 customers
- New customers
- 1 customers
- Starting monthly recurring revenue
- $8,000.00
- Churned MRR
- $900.00
7.5%
customer churn rate
- Revenue churn rate
- 11.3%
- Ending customers
- 38
- Net customer change
- -2
Average starting MRR is 8,000 ÷ 40 = $200. The three lost accounts took 900 ÷ 3 = $300 each. They were 300 ÷ 200 = 1.5 times the average account, so revenue churn sits above customer churn.
The headcount still fell. One new customer did not replace three lost customers.
Example 3: a book of 1,200 customers
Inputs: start 1,200, lost 48, new 90, starting MRR $180,000, churned MRR $5,400.
Customer churn: 48 ÷ 1,200 = 0.04 = 4%
Revenue churn: 5,400 ÷ 180,000 = 0.03 = 3%
Ending customers: 1,200 − 48 + 90 = 1,242
Net change: 90 − 48 = +42
Average starting MRR is 180,000 ÷ 1,200 = $150. Lost accounts averaged 5,400 ÷ 48 = $112.50. The accounts that left were smaller than average, so the dollar rate is the quieter of the two.
Ending headcount is higher by 42. The churn rate is still 4%, because the rate uses 1,200.
Example 4: what if the same 15 accounts are larger
Hold Example 1 and change only churned MRR, from $1,800 to $7,200. Headcount inputs stay put.
Customer churn stays 15 ÷ 250 = 6%
Revenue churn: 7,200 ÷ 30,000 = 0.24 = 24%
Ending customers stay 257. Net change stays +7.
Calculator result
Customer churn rate
- Churned MRR
- $7,200.00
6%
customer churn rate
- Revenue churn rate
- 24%
- Ending customers
- 257
- Net customer change
- 7
Those 15 accounts now average 7,200 ÷ 15 = $480. That is 480 ÷ 120 = 4 times the $120 average in Example 1. The headcount story is unchanged. The dollar story is four times as large, because 24 ÷ 6 = 4.
Fig 3 · 1/2
Customer churn beside revenue churn
Same period on each book. Rates in percent.
Churn rate
- Customer
- Revenue
| Category | Customer | Revenue |
|---|---|---|
| 250 accounts | 6% | 6% |
| Studio of 40 | 7.5% | 11.3% |
| Larger accounts | 6% | 24% |
| One big account | 1.6% | 22% |
On the default book both rates are 6%.
When larger accounts leave, revenue churn pulls away from the headcount rate.
The fourth pair is Example 9 below. Customer churn there is 1.6%. Revenue churn is 22%.
Example 5: the mistake of dividing by the ending count
Take Example 1 again. Someone divides the 15 lost customers by the 257 at the end.
15 ÷ 257 = 0.058365, which rounds to 5.8% at one decimal.
The formula’s denominator is 250, so the rate is 6%. The gap is 6 − 5.8 = 0.2 percentage points on this book. It grows when the new-customer count is large, because those new accounts inflate the ending count and shrink the mistaken rate.
A second slip nets the new customers before the division: (15 − 22) ÷ 250 = −7 ÷ 250 = −2.8%. The page will not print that. Its customer churn stays 6%. Its net customer change is the separate line, +7.
Example 6: a quarter, not a month
Inputs: start 80, lost 10, new 6, starting MRR $24,000, churned MRR $4,500. The period is one quarter. Every input is for that quarter.
Customer churn: 10 ÷ 80 = 0.125 = 12.5%
Revenue churn: 4,500 ÷ 24,000 = 0.1875, which the page rounds to 18.8%
Ending customers: 80 − 10 + 6 = 76
Net change: 6 − 10 = −4
Average starting MRR is 24,000 ÷ 80 = $300. Lost accounts averaged 4,500 ÷ 10 = $450. Revenue churn is higher because those accounts were larger.
Leave this 12.5% as a quarterly rate. Dividing it by 3 to invent a month is a different calculation. Run the month on the month’s own counts.
Example 7: nobody left
Inputs: start 180, lost 0, new 5, starting MRR $15,000, churned MRR $0.
Customer churn: 0 ÷ 180 = 0%
Revenue churn: 0 ÷ 15,000 = 0%
Ending customers: 180 − 0 + 5 = 185
Net change: +5
A zero rate means the opening base stayed. The five new customers are growth on the ending line. They are not a negative churn rate.
Example 8: a hard month
Inputs: start 60, lost 18, new 4, starting MRR $12,000, churned MRR $4,800.
Customer churn: 18 ÷ 60 = 0.30 = 30%
Revenue churn: 4,800 ÷ 12,000 = 0.40 = 40%
Ending customers: 60 − 18 + 4 = 46
Net change: 4 − 18 = −14
Average starting MRR is 12,000 ÷ 60 = $200. Lost accounts averaged 4,800 ÷ 18 = $266.67. The dollar rate is higher, and the book is smaller by 14 customers.
Fig 4 · 1/3
Ending customers after the period
New customers are already inside these counts. They did not change the churn rate.
Ending customers
Defaults
257
Nobody left
185
One large account
512
The default book ends at 257.
The quiet month ends at 185. The book that lost one large account ends at 512.
Example 9: a low logo rate and a high dollar rate
Inputs: start 500, lost 8, new 20, starting MRR $100,000, churned MRR $22,000.
Customer churn: 8 ÷ 500 = 0.016 = 1.6%
Revenue churn: 22,000 ÷ 100,000 = 0.22 = 22%
Ending customers: 500 − 8 + 20 = 512
Net change: 20 − 8 = +12
Average starting MRR is 100,000 ÷ 500 = $200. The eight lost accounts took 22,000 ÷ 8 = $2,750 each. That is 2,750 ÷ 200 = 13.75 times the average account. Headcount rose by 12. The recurring book lost 22% of its starting MRR.
If you only read 1.6%, you miss the account that carried the dollars.
Example 10: lost customers above the opening count
Inputs: start 20, lost 30, new 4, starting MRR $5,000, churned MRR $5,000.
Customer churn: 30 ÷ 20 = 1.5 = 150%
Revenue churn: 5,000 ÷ 5,000 = 100%
Ending customers: the raw count is 20 − 30 + 4 = −6. The page floors that at 0.
Net change: 4 − 30 = −26
A rate above 100% means the lost count is larger than the opening count. That can be a bad export, or a rule that counts customers who joined and left inside the period. The formula still divides by the start. Check the export before you treat 150% as the month.
Example 11: a year, and the mistake of dividing by 12
Inputs for one year: start 400, lost 96, new 40, starting MRR $48,000, churned MRR $14,400.
Customer churn: 96 ÷ 400 = 0.24 = 24%
Revenue churn: 14,400 ÷ 48,000 = 0.30 = 30%
Ending customers: 400 − 96 + 40 = 344
Net change: 40 − 96 = −56
Dividing the year by 12 gives 24 ÷ 12 = 2% on customers and 30 ÷ 12 = 2.5% on revenue. Those are not the calculator’s monthly rates. The page was given a year, and it returned 24% and 30% for that year. A month needs the month’s own starting count, lost count, and MRR. Run them as two periods.
What is a good churn rate?
This calculator does not set a target rate. The SBA page linked above does not name a universal churn percentage either. Compare the two rates on your own period. A 6% customer rate with a 6% revenue rate is a different month from a 6% customer rate with a 24% revenue rate, which is Example 1 beside Example 4.
Cash still in the bank is a separate question. The cash runway calculator and the runway post start from the cash balance, not from the churn rate.
The eleven results side by side
| Example | Start | Lost | New | Starting MRR | Churned MRR | Customer churn | Revenue churn | Ending | Net |
|---|---|---|---|---|---|---|---|---|---|
| 1. Defaults | 250 | 15 | 22 | $30,000 | $1,800 | 6% | 6% | 257 | +7 |
| 2. Studio | 40 | 3 | 1 | $8,000 | $900 | 7.5% | 11.3% | 38 | −2 |
| 3. Book of 1,200 | 1,200 | 48 | 90 | $180,000 | $5,400 | 4% | 3% | 1,242 | +42 |
| 4. Larger accounts | 250 | 15 | 22 | $30,000 | $7,200 | 6% | 24% | 257 | +7 |
| 5. Divide by 257 | 250 | 15 | 22 | $30,000 | $1,800 | 5.8% wrong | 6% on the formula | 257 | +7 |
| 6. One quarter | 80 | 10 | 6 | $24,000 | $4,500 | 12.5% | 18.8% | 76 | −4 |
| 7. Nobody left | 180 | 0 | 5 | $15,000 | $0 | 0% | 0% | 185 | +5 |
| 8. Hard month | 60 | 18 | 4 | $12,000 | $4,800 | 30% | 40% | 46 | −14 |
| 9. One large account | 500 | 8 | 20 | $100,000 | $22,000 | 1.6% | 22% | 512 | +12 |
| 10. Lost above the start | 20 | 30 | 4 | $5,000 | $5,000 | 150% | 100% | 0 | −26 |
| 11. One year | 400 | 96 | 40 | $48,000 | $14,400 | 24% | 30% | 344 | −56 |
Example 5’s 5.8% is the mistaken denominator. The formula on those same inputs is still 6%. Example 11’s year stays 24% and 30%. Dividing either rate by 12 is a different number.
The monthly recurring revenue calculator is where new, expansion, and churned MRR become an ending run-rate. Churn on this page is only the share that left. Working capital and the cash conversion cycle, in the posts linked below, are the balance-sheet side of the same business.