COVID infection after a negative rapid antigen test

Probability:
0.209%
Odds:
1 to 478
dBan
−26.8 dBan

In this hypothetical group of 100,000 people at 0.5% prevalence, about 99,110 test negative. The test misses 207 infections among them, about one infected person in 479 negative results.

Calculation

p = (0.005 × (1 − 0.586)) / [(0.005 × (1 − 0.586)) + (0.995 × 0.994)] ≈ 0.00209

Assumptions

The calculation starts from the hypothetical 0.5% prevalence and uses pooled sensitivity 0.586 and specificity 0.994 for asymptomatic people with suspected exposure. These historical pooled estimates combine different tests and studies through February 2022. Performance varies by kit, timing, sampling, and setting. This calculation is not a personal diagnosis.

Sources

  1. Cochrane: accuracy of rapid antigen tests for COVID-19 Dinnes et al., version 4, published 28 November 2025, with studies searched through 17 February 2022