Yes, run calculations on this page free 10 times a day, and up to 10 times a day across all the tools, while designing experiments, running them against real users, and reading confidence intervals sit inside the free Intempt plan.

What method does it use?

Standard frequentist sample-size math with configurable alpha and power, defaulting to alpha 0.05 and power 0.80.

Founders and heads of growth running their own tests at seed to Series A. The usual blocker is not the math, it's the data: stitching HubSpot free plus Mailchimp plus Calendly plus GA4 with duct tape leaves no single view of ad click to signup to trial to paid, so there is nothing solid to power a test against.

Do I need an analyst to run a test properly?

No, and that is the point of showing the math. The sample size, alpha, power, and confidence interval are all on the page, so a test can be sized and defended without a CRO agency or an analyst on staff. Inside Intempt the same numbers become guardrails: hypothesis, primary metric, guardrail metric, and stopping rule are fixed before launch, so an underpowered test cannot ship.

How is this different from other calculators?

Other calculators give you numbers, whereas this tool hands the parameters to a system that runs the actual experiment with hypothesis, guardrail, and exit rule.

Can I save the calculation?

Use the toolbar above the result to copy or download as .md, .txt, .html, or PDF, and nothing is stored unless you sign up for Intempt.

What happens after I sign up for Intempt?

The Experimentation Lead agent designs the test with a hypothesis and a guardrail metric, runs it against the product events already connected on day one, tracks significance live, and drafts the next experiment from what shipped.

Do I have to use Intempt to get value from this tool?

No, the calculator works on its own. Intempt adds the guardrails a static sample size can't hold - a fixed stopping rule, a guardrail metric watched alongside the primary one on the Org plan - and the funnel data to run against, with no analyst to staff.

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