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What losing members actually costs you

Every gym owner knows people leave. Almost none can say what it costs. Four numbers you already know, and the year in front of you priced out. No sign-up, and the arithmetic is printed underneath so you can check it.

Your numbers

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Everyone paying you today.

Total monthly revenue ÷ active members.

In a typical month, not your worst one.

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What that costs you

€21,060

Revenue lost over 12 months

Monthly churn rate5%
Average member lifetime20 months
Lifetime value per member€900
Cost of replacing them for a year€2,160

Keeping one more member a month is worth €3,510 over the same year.

See how Theron surfaces this →

How it is calculated

Nothing here is proprietary and nothing is rounded in our favour. Take a gym with 120 members paying €45 a month, losing 6 members a month.

Monthly churn rate
Members lost ÷ active members = 6 ÷ 120 = 5%
Average member lifetime
1 ÷ churn rate = 1 ÷ 0.05 = 20 months
Lifetime value per member
Fee × lifetime = €45 × 20 = €900
Revenue lost over 12 months
Fee × members lost per month × 78 = €45 × 6 × 78 = €21,060

Where the 78 comes from

This is the part most churn calculators get wrong, in both directions. A member who leaves in January is not missing for one month — they are missing for the rest of the year. If six people leave every month and you do not replace them, you are short six subscriptions in month one, twelve in month two, and seventy-two by month twelve. Add those up and you get 1 + 2 + … + 12 = 78 monthly subscriptions for every member you lose per month.

The opposite mistake is multiplying annual leavers by lifetime value, which is what most “cost of churn” tools do. That counts revenue from years you have not reached, and produces a figure so large that the owner stops believing it. The headline number here is deliberately the smaller, checkable one: twelve months, against your own bank statements.

The same arithmetic is what makes the last line worth reading. Keeping one more member per month is worth one fee × 78 over the year — at €45 a month, €3,510 for a single person. That is usually less work than finding one more new member.

What to do with the number

The number is only useful if it changes what you look at on a Monday morning. Members almost never cancel on impulse: attendance falls off first, and the cancellation arrives weeks later as the last event in the story rather than the first. By the time it reaches you, the decision was made a month ago.

Which means the practical question is not “how do I win people back” but “can I see someone drifting while a message from me still means something”. That needs attendance and renewal dates on the same screen — a spreadsheet has both numbers and cannot put them side by side.

How Theron shows this

Related: gym management software · gym CRM · pricing

FAQ

Gym churn — common questions

What counts as a good churn rate for a gym?▾
Most independent gyms and studios sit somewhere between 3% and 8% a month, which is an average member lifetime of roughly twelve to thirty months. Below 3% is strong. Above 10% means you are replacing your entire membership inside a year, and almost all of your marketing budget is buying back people you already had. Compare yourself against your own last six months rather than an industry figure — the definitions vary too much between sources to benchmark against safely.
Why does the calculator multiply by 78 instead of by 12?▾
Because a member who leaves in January is missing for eleven more months, not one. If you lose the same number of people every month and do not replace them, month one costs you one cohort of fees, month two costs you two, and month twelve costs you twelve — so across the year you miss 1+2+…+12 = 78 monthly subscriptions per member lost per month. Multiplying by 12 would only count each leaver once and understate the year badly.
Is this the same as lifetime value?▾
No, and the difference matters. Lifetime value is the fee times the expected lifetime, which is revenue stretching years into the future. The headline figure here is only the next twelve months, which is a number you can check against your own bank statements. Both are shown, but the twelve-month figure is the one to argue with.
Do I need to sign up to use it?▾
No. There is no form, no email, and no account. The calculation runs in your browser and nothing you type is sent to us or stored anywhere.
What actually reduces churn once I know the number?▾
The single biggest lever for a small gym is noticing early. Members stop attending weeks before they cancel, so the cancellation is the last event in the story rather than the first. If you can see falling attendance next to an upcoming renewal date, a message from you still means something. That is what Theron surfaces; it does not send automated win-back campaigns or score churn risk.
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