Trial Conversion Rate Calculator

Every trial costs money, converted or not.

Every trial costs money, converted or not. The effective cost of a paid subscriber is the total cost of all trials divided by the ones that converted.

Written and maintained by Mohit PatelLast checked August 4, 2026How we build these

Currency

Trials started

Converted to paid

Cost of servicing a trial

Cost to get a trial

Lifetime value of a paid subscriber

Trial conversion rate

24%

$99.17 per paid subscriber

Trials1,400

Converted336

Effective acquisition cost$99.17

LTV to CAC3.43:1

Every trial costs money whether it converts or not, so the effective acquisition cost is the total trial cost divided by conversions, $99.17 here against $23.80 per trial. Raising conversion reduces it far faster than reducing trial cost does.

How the Trial Conversion Rate Calculator works

The effective cost of a paid subscriber is the total cost of all trials divided by the ones that converted. Raising conversion reduces it far faster than reducing the cost of servicing each trial does.

Also known as: free trial conversion rate · trial to paid conversion · what percentage of trials convert

The calculation itself

Trial conversion rate is trials converting to paid divided by trials started: converted ÷ started × 100.

The denominator choice matters: trials started, trials that activated, or trials that reached the end of the period all give different figures and all are used.

Effective CAC = cost per trial ÷ trial conversion rate, which is what connects the metric to acquisition economics.

The same thing with real figures

1,400 trials producing 420 paid subscribers is a 30% conversion rate. At $17.40 per trial, effective CAC is $58.

Improving conversion to 38% drops effective CAC to $45.79, a 21% improvement in acquisition efficiency with no change in traffic cost.

That same improvement through media would require cutting cost per trial from $17.40 to $13.74, which is considerably harder.

The trial experience is therefore usually a cheaper lever than the acquisition channel, and it is the one most often left alone after launch.

The catch

Free trials with no card required convert at a fraction of the rate of card-required trials, so the two are not comparable. The first produces more trials and a lower rate; the second fewer and higher.

What matters is subscribers per dollar spent, and either model can win depending on the traffic and the product.

Applying it

Compare models on effective CAC rather than on conversion rate, since a low rate on cheap trials can beat a high rate on expensive ones.

Then measure activation, the share of trials that reach the point of experiencing the product's value, since that is the step conversion actually depends on.

Why activation predicts conversion better than anything else

Trials that never reach a meaningful first use convert at near zero regardless of how long they run or how many emails they receive. The determinant is whether the product did something useful during the trial.

Identifying the specific action that separates converters from non-converters, and it is usually one or two concrete steps, turns trial optimisation from a general problem into a specific one.

The work then becomes getting more trials to that action quickly, through onboarding, guided setup or removing configuration barriers. That is more productive than extending the trial length or adding reminder emails, both of which are common responses that address the symptom rather than the cause.

Trial length is worth testing rather than inheriting, since shorter trials frequently convert better by creating urgency while longer ones suit products requiring setup.

The right length depends on how quickly the product can demonstrate value, which is measurable from when converting trials took their key action.

Requiring a card at signup shifts the population rather than the product, so comparing conversion rates across that change measures the selection effect rather than any improvement.

Following non-converting trials for several months often finds a meaningful share convert later, which means the immediate rate understates what the trial eventually produces.

Comparing conversion by traffic source frequently shows a wide spread, and reallocating acquisition toward the sources producing converting trials improves effective CAC without any change to the trial itself.

Where to go next

The Trial Conversion Rate question rarely arrives on its own. These are the ones that usually come with it:

Subscription Payback Period Calculator — With churn, and the cash a cohort ties up.
Membership Pricing Calculator — Perceived value has to be a multiple of price.
Subscription Retention Calculator — Most of the loss happens in month one.
Etsy Fee Calculator — Every Etsy fee on one sale, itemised.

Not financial advice. Marketplace fees change, and they vary by country, plan and seller status. Every rate here is an editable default, not a quoted price, check the platform's current fee schedule before you price a product against it. This is not tax or business advice.

Frequently asked questions

What is a good trial conversion rate?

Free trials without a card commonly convert 15% to 25%; trials requiring a card convert far higher but attract fewer starts. Neither is better in the abstract, compare the cost per paid subscriber.

Should I require a card up front?

It raises conversion of trials and lowers the number of trials. Which produces more paid subscribers per pound of acquisition spend is an empirical question worth testing rather than assuming.

How long should a trial be?

Long enough to reach the moment the product becomes useful, and no longer. Extending a trial past that point mostly delays the decision and increases the cost of servicing it.

Why does trial cost matter?

Because you pay to acquire every trial and to service every trial, whether or not it converts. A 20% conversion rate means five times the trial cost sits behind each paid subscriber.