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LOD / LOQ Calculator

Calculate the limit of detection and limit of quantitation from a calibration curve or replicate blanks, following ICH Q2 (LOD = 3.3σ/S, LOQ = 10σ/S).

Calibration standards

Concentration (x)Signal (y)

Response standard deviation (σ)

ICH Q2 conventions: 3.3 for LOD, 10 for LOQ.

Limit of detection (LOD)

0.2238

3.3 · σ / S — lowest reliably detectable concentration

Limit of quantitation (LOQ)

0.6781

10 · σ / S — lowest reliably quantifiable concentration

Slope (S)

0.1963

σ (response SD)

0.01331

Intercept

0.01429

0.99895

Formula reference

LOD: LOD = 3.3 · σ / S
LOQ: LOQ = 10 · σ / S
σ = response standard deviation, S = calibration slope.