How it works
Customer retention rate is the percentage of existing customers a business keeps over a period, calculated as the ending customers minus new customers acquired, divided by the customers at the start. Start with 1,200, finish with 1,260 having signed 240 new ones, and retention is 85% — the original base shrank by 180 even while the total grew. Subtracting new arrivals is what makes the metric honest: without it, aggressive acquisition paints a leaking bucket as growth. Retention deserves its reputation as the quietest powerful lever in business economics. Keeping a customer costs a fraction of replacing one, retained customers buy more over time and refer others, and the effect compounds — a base retaining 90% versus 80% diverges dramatically over a few years on identical acquisition. The calculator pairs retention with its mirror, churn, and the raw counts of who stayed and left. Three usage rules keep readings meaningful. Measure over fixed windows and keep the window constant, since the same business shows very different rates monthly versus annually. Remember retention counts surviving customers, not repeat purchases — someone active without reordering still counts as retained here. And on small bases, a handful of departures swings the percentage wildly, so read small-sample months gently.
Formula
Retention rate = ((customers at end - new customers) / customers at start) x 100 | churn rate = 100% - retention rate
Tips
- Fix the measurement window — monthly and annual retention tell different stories.
- Acquisition can mask churn: always separate kept customers from new ones.
- Win-backs returning mid-period can push retention over 100%; report them separately.
- Small customer bases swing wildly — judge trends, not single-month percentages.
- Pair retention with lifetime value; the two multiply into your marketing ceiling.
Frequently asked questions
- What is customer retention rate?
- The percentage of your existing customers who stay with you over a period. Of 1,200 starting customers, if 1,020 remain at the end after excluding new signups, retention is 85%. It measures loyalty independent of how many new customers marketing brings in.
- How do you calculate customer retention rate?
- Subtract new customers acquired from total customers at the end, divide by customers at the start, and multiply by 100: ((1,260 - 240) / 1,200) x 100 = 85%. The subtraction excludes new arrivals so the rate describes only the original group.
- What is a good customer retention rate?
- Strongly industry-shaped: subscription software often targets 90%+ annually while retail runs far lower on any window. More useful than a universal benchmark is your own trend — rising retention at constant acquisition compounds base growth visibly within a year.
- What's the difference between retention rate and churn rate?
- They are mirrors of the same fact: churn is 100% minus retention. An 85% retention rate is a 15% churn rate. Teams track both because churn frames problems (who we lose) while retention frames goals (who we keep).
- Is retention rate the same as repeat purchase rate?
- No. Retention counts customers still present at period end, however they behaved; repeat purchase rate counts customers who ordered again. A customer active on support but not reordering is retained yet not repeating — the two metrics catch different failures.