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Risk Difference Calculator

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Compare two event-rate groups and review the signed risk gap, absolute gap, and group risks together.

How to use

  1. Enter event counts and totals for group A and group B.
  2. Calculate to review each group risk, the signed difference, and the absolute difference.
  3. Use the sign first, then the absolute gap if you only care about magnitude.

Wave 12 clinical bridge

Compare two event-rate groups

The share URL stores only decimal settings.

Enter event counts and totals for both groups.

Where this fits

Use this page when you want an absolute gap in percentage points without converting to NNT or NNH. Relative risk vs odds ratio adds ratio-based interpretation. NNH converts harm-sized differences into people-needed language.

FAQ

What does this page calculate?

It compares two event-rate groups and reports each group risk, the signed risk difference, and the absolute risk difference.

How is the sign defined?

The page reports group A risk minus group B risk. A positive value means group A has the higher event rate.

Is this the same as relative risk?

No. Risk difference is an absolute gap in percentage points. Relative risk is a ratio. Both are useful, but they answer different questions.

Does the share URL include my counts?

No. The share URL stores only light settings such as decimal places. Count inputs stay in your browser.