Free marketing & patients tool
Patient Retention Rate Calculator (Churn and Rebooking)
Patient retention rate is the share of your starting patients who are still active at the end of a period, ignoring new ones: (end − new) ÷ start. If you began with 800 patients, added 260 and finished with 880, retention is (880 − 260) ÷ 800 = 77.5%, and churn is 22.5%. Enter your counts below, or switch to rebooking or membership churn.
Prepared by Prospyr · Reviewed October 3, 2026 · Free, no sign-up, runs in your browser
First visits during the period.
Adds a dollar figure for lapsed patients.
Patient retention rate
77.5%
Churn rate: 22.5%. 180 of 800 patients did not return.
Retained
620
Five points higher
+40 patients
retention of 82.5%
A math aid. Results depend on how you define an active patient and a cancellation, so use the same definition every period.
Retention rate and churn rate formulas
- Retention rate = (patients at end − new patients) ÷ patients at start
- Churn rate = 1 − retention rate = patients lost ÷ patients at start
- Rebooking rate = returning patients ÷ patients seen in the prior period
- Monthly membership churn = cancellations in the month ÷ members at the start of the month
Worked example. A practice starts the year with 800 active patients, sees 260 new patients and ends with 880. Retained patients: 880 − 260 = 620. Retention: 620 ÷ 800 = 77.5%. Churn: 22.5%, or 180 patients. At $600 a patient a year, those 180 patients are about $108,000 of yearly revenue to win back or replace.
New patients are subtracted because they were not in the starting group. Counting them would hide churn.
Customer churn rate for memberships
A membership program loses people every month, and the loss compounds. Annual retention is (1 − monthly churn)12. The average length of a membership is 1 ÷ monthly churn, and revenue per member over that length is the monthly fee × that number.
| Monthly churn | Annual retention | Average membership |
|---|---|---|
| 2% | 78.5% | 50 months |
| 4% | 61.3% | 25 months |
| 6% | 47.6% | 16.7 months |
| 8% | 36.8% | 12.5 months |
A change from 4% to 2% monthly churn doubles the average membership. See Prospyr's memberships feature for how recurring billing and pause options are handled.
Defining an active patient so the number means something
The formula is simple. The hard part is the definition. A patient who gets neurotoxin every four months is active at six months; a patient who comes for a yearly laser package may not be. Pick one rule, such as a visit in the last 12 months, and write it down. Changing the rule changes the rate without changing a single patient.
Run the calculation on the same dates each period, and compare like with like, by service line if you can. Prospyr's analytics report patient visits and returns, and the blog guide to the patient retention rate covers ways to raise it.
Frequently asked questions
How do you calculate patient retention rate?
Subtract new patients from your ending patient count, then divide by your starting count: retention = (end − new) ÷ start. With 800 at the start, 260 new and 880 at the end, 620 were retained, so retention is 77.5%. Use the same definition of an active patient for every period.
What is the churn rate formula?
Churn rate is 1 minus the retention rate, or patients lost ÷ patients at the start. If 180 of 800 patients did not return, churn is 22.5%. For memberships, divide cancellations during the month by members at the start of the month.
What is the difference between retention rate and rebooking rate?
Retention compares counts at the start and end of a period. Rebooking asks a narrower question: of the patients you saw last period, how many came back. Rebooking is easier to compute from a visit report, so many practices track it every quarter or year.
How do I calculate monthly membership churn?
Divide the members who cancelled during the month by the members you had at the start of the month. Six cancellations out of 150 members is 4% monthly churn. Leave out people who joined that month, since they were not in the starting group.
How long does the average member stay at a given churn rate?
Divide 1 by the monthly churn rate. At 4% churn the average membership lasts 25 months. Annual retention at that pace is (1 − 0.04)^12, or about 61%, because churn compounds each month.
What is a good patient retention rate for a med spa?
There is no single benchmark that fits every practice, because the answer depends on how you define an active patient and what services you offer. Track your own number each quarter with a fixed definition and watch the trend. Published benchmarks from vendors are not comparable to yours unless they use your definition.
Why does retention matter to a practice?
Keeping a patient costs less than finding a new one. A Harvard Business Review article reports that acquiring a customer can cost five to 25 times more than retaining one. For a practice, the lapsed-patient figure in the calculator shows what that gap is worth in revenue.
Sources and scope
- The Value of Keeping the Right Customers. Amy Gallo, Harvard Business Review, October 29, 2014
Source for the statement that acquiring a customer can cost five to 25 times more than retaining one. The retention and churn formulas above are standard arithmetic.
A math aid. Results depend on your definition of an active patient. This tool does not predict future retention.