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Find the real field size behind your test.

Map assigned variants, markets, and mutually exclusive cells before estimating invitations or cost.

Alternatives assigned as separate test conditions.
Markets that require separate conclusions.
Use 1 for overlapping cuts such as age and device within the same sample.
A planning target, not a power calculation.
Expected share removed by pre-specified quality rules.
Share of delivered invitations expected to begin the screener.
Share of screener starters expected to meet eligibility.
Share of eligible starters expected to complete.
User-entered planning assumption; not a market benchmark.
Analysis cells4
Usable completes400
Field target455
Estimated invitations2,185
Estimated field costUSD 1,137.50

Calculation: variants × markets × mutually exclusive segment cells × usable completes per cell. The field target divides usable completes by 1 minus the expected exclusion rate. Invitations divide that target by screener-start rate × incidence × eligible completion rate. Cost multiplies the field target by your entered cost per complete.

Overlapping reporting cuts do not automatically multiply the design. This is a field-size and cost planner—not a statistical power or minimum-detectable-effect calculator. Calculator inputs remain in page memory and are not sent or written to site storage by this application.

Use cells deliberately

If the U.S. and Canada require separate conclusions, those are separate market cells. Mutually exclusive groups also multiply the design when each requires its own usable base. Overlapping cuts—such as age and device within the same respondents—should not both be entered as separate cell multipliers.

Pre-specify before fielding

Write the primary comparison, exclusion rules, minimum cell sizes, weighting approach, and stopping rule before results are visible. Confirm statistical power separately using the intended outcome, expected variance, test, allocation, and minimum effect worth detecting.