Two ways to describe the light.
Convert between absorbance and percentage transmittance. See the relationship behind the result.
10% of incident light is transmitted in this idealised model.
A logarithmic relationship
Transmittance T is the fraction of incident radiant power that passes through the sample. Percentage transmittance is 100 × T. Absorbance uses a base-10 logarithm: A = −log₁₀(T).
At A = 1, 10% is transmitted. At A = 2, only 1% is transmitted. A = 0 corresponds to 100% transmittance.
Read the guide ↗What this calculator assumes
This idealised converter accepts nonnegative absorbance and 0 < %T ≤ 100. Zero transmittance has no finite absorbance. Very high absorbance can produce numbers too small for a computer to represent; that is not proof of physically zero transmission.
Negative measured absorbance can occur relative to a blank. This calculator’s range does not judge an instrument or sample. Definition: IUPAC Gold Book.
The beam is illustrative and does not predict perceived sample colour.