Sample size calculator

Calculate before you collect. Discovering the sample was too small after collection is the point at which it can no longer be fixed.

Survey estimating a proportion You want to know what percentage of a population has a given characteristic. Comparing two groups with a measured outcome For example scores, height or time — comparing means between two groups. Comparing two groups with a yes/no outcome For example a pass rate or a recovery rate — comparing proportions between two groups.

What matters most Compute from the smallest difference worth caring about, not from the difference you hope to see. People almost always hope for a larger effect than the real one, so that approach systematically produces samples that are too small — and you only find out once the data is collected.

🤝 Next step — when you need a real person working with you

The tool above identifies the problem. These packages address exactly that problem.

One-to-one academic mentoring 800,000 VND – 2M VND / hour

Work directly with someone who has already been through the stage you are in. Charged by the hour, no long-term commitment.

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📝Draft a research proposal

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