How to calculate trial conversion rate
Take the trials that ended during the period, then count how many of them became paying: the first paid invoice was issued and collected. Divide the paying count by the trials that ended.
Count only trials that have finished. The simplest way is to group trials by the month they ended: a trial that started on March 25 and ends in April belongs in April's number, because that is when the customer decided. You can also follow the trials that started in a month, but only once every one of them has ended.
How the trial starts changes the number. In an opt-out trial the customer gives a card at signup and pays automatically unless they cancel. In an opt-in trial no card is taken, and the customer has to come back and choose to pay. The two produce very different rates, so measure them separately and never compare one with the other.
Trial conversion rate = trials that became paying subscriptions ÷ trials that ended in the period
Worked example
A business runs 14 day opt-out trials with a card taken at signup. In April, 120 trials were due to end.
- Trials that ended in April
- 120
- Canceled before the trial ended
- 63
- First charge failed and was never recovered
- 3
- Became paying: 120 − 63 − 3
- 54
- Trial conversion rate: 54 ÷ 120
- 45.0%
The 3 failed first charges are customers who meant to pay. Payment recovery, not onboarding, is the lever for these.
Why trial conversion rate matters
For a product sold through trials, this is the number that turns signups into revenue. Doubling signups and halving conversion leaves you with the same number of paying customers and twice the support load.
It also shows where to work. A low rate with many cancellations in the last days points at onboarding or the trial length; a low rate with many failed first charges points at payment recovery; a low rate in an opt-in trial may mean customers simply forgot to come back.
Common mistakes
- Counting trials that are still running A trial that has not ended yet has not had a chance to convert. Divide by trials that have ended, or wait until a start-month group has fully finished.
- Mixing opt-in and opt-out trials A trial that needs a card and one that does not measure different decisions. Report them apart.
- Counting a converted trial before it pays A trial that ended with a failed charge is not a paying customer yet. Count it when the first invoice is paid.
- Comparing yourself with other companies Conversion depends on price, audience, trial length and whether a card is taken. Track your own rate over time instead.