Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Projected conversion rate at new trial length
19.1%
Projected converted customers/month
190.8
Monthly ARR impact vs current trial
$12,960
Additional days until revenue books
7
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How to use this
- 1Enter monthly trial signups.
- 2Enter current conversion rate at current trial length (%).
- 3Enter current trial length (days).
- 4Enter new trial length to test (days).
- 5Enter conversion elasticity per week of trial change (%).
- 6Enter annual value per converted customer ($).
- 7Read your projected conversion rate at new trial length on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
Trial length is one of the few growth levers you can change with a single config flag, and it trades off two things: conversion rate and time-to-revenue. Shorter trials (7-10 days) create urgency and get revenue booked faster, but can cut off users who needed more time to reach an 'aha moment,' especially for products with a longer setup or onboarding curve. Longer trials (21-30 days) usually lift conversion for complex products by giving users room to actually integrate the tool into a workflow, but they delay cash collection and let some users extract value without ever paying. This calculator applies a simple elasticity assumption (percentage change in conversion per week of trial length change) so you can compare scenarios; the real elasticity is specific to your product and should come from an actual A/B test, but this gives you a reasonable planning estimate and shows why 'just extend the trial' isn't automatically the right answer once you account for delayed revenue timing.
Worked example
Using the values the calculator loads with:
Inputs
- Monthly trial signups: 1000
- Current conversion rate at current trial length: 18 %
- Current trial length: 14 days
- New trial length to test: 21 days
- Conversion elasticity per week of trial change: 6 %
- Annual value per converted customer: 1200 $
Results
- Projected conversion rate at new trial length: 19.1%
- Projected converted customers/month: 190.8
- Monthly ARR impact vs current trial: $12,960
- Additional days until revenue books: 7
What each field means
Inputs
- Monthly trial signups
- The monthly trial signups used in the calculation. Starts at 1000 so you have a working example on load.
- Current conversion rate at current trial length (%)
- The current conversion rate at current trial length used in the calculation, measured in %. Starts at 18 % so you have a working example on load. Accepted range: 0.1–100 %.
- Current trial length (days)
- The current trial length used in the calculation, measured in days. Starts at 14 days so you have a working example on load.
- New trial length to test (days)
- The new trial length to test used in the calculation, measured in days. Starts at 21 days so you have a working example on load.
- Conversion elasticity per week of trial change (%)
- The conversion elasticity per week of trial change used in the calculation, measured in %. Starts at 6 % so you have a working example on load. Accepted range: -50–50 %.
- Annual value per converted customer ($)
- The annual value per converted customer used in the calculation, measured in $. Starts at 1200 $ so you have a working example on load.
Results
- Projected conversion rate at new trial length
- Returned as a percentage and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Projected converted customers/month
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Monthly ARR impact vs current trial
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Additional days until revenue books
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Where does the elasticity number come from?
It should come from an actual A/B test on your product — run two trial lengths against comparable cohorts for at least one full sales cycle and measure the conversion delta. Without test data, use this calculator with a conservative estimate (3-8% per week) and treat the output as a rough planning scenario, not a forecast.
Does a longer trial always increase total conversions?
No — past a certain point, longer trials just delay the same eventual conversion decision without meaningfully improving it, while some users complete everything they needed within the product during the free period and never convert at all. Complex, integration-heavy products benefit more from longer trials than simple, immediately-useful ones.
What's the real cost of a longer trial beyond lower urgency?
Cash timing. Every extra week of trial length pushes first revenue back a week for the whole cohort, which matters for cash-constrained companies and for how quickly a paid-conversion cohort shows up in that month's bookings and reporting.
Should trial length vary by segment?
Often yes — self-serve SMB users typically need less time to evaluate and convert faster with shorter trials (7-14 days), while mid-market and enterprise buyers going through internal evaluation and stakeholder buy-in often need longer trials or a sales-assisted proof-of-concept period (30+ days) to reach a decision.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
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Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Trial Length Conversion Impact Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/trial-length-conversion-impact
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/trial-length-conversion-impact" target="_blank" rel="noopener">Trial Length Conversion Impact Calculator — RevenueLab</a> (2026).</p>
Source: [Trial Length Conversion Impact Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/trial-length-conversion-impact) (2026).