convertimate Absorbance

Absorbance to percent transmittance

Type a value in A to get it in %T instantly.

10%T

That's 3.2× as dark as the best measuring range, while a strongly colored sample is 10× darker. About 10% of the light gets through.

What it means

How much light gets through?

Above about 2 the detector is measuring very little light, and stray light dominates. Dilute the sample rather than trusting the reading.

The math

How to convert A to %T

Absorbance is a logarithm of transmittance: A = −log₁₀(T), and back again %T = 10^(−A) × 100. One absorbance unit is a tenfold cut.

Example: 1 A = 10 %T.

Every unit

Your absorbance in every unit

Tables

A to %T conversion table

A to %T conversion table
A%T
0.01 A97.7237 %T
0.05 A89.1251 %T
0.1 A79.4328 %T
0.3 A50.1187 %T
0.5 A31.6228 %T
0.7 A19.9526 %T
1 A10 %T
1.5 A3.16228 %T
2 A1 %T
3 A0.1 %T
4 A0.01 %T
%T to A conversion table
%T to A conversion table
%TA
0.01 %T4 A
0.05 %T3.30103 A
0.1 %T3 A
0.3 %T2.52288 A
0.5 %T2.30103 A
0.7 %T2.1549 A
1 %T2 A
1.5 %T1.82391 A
2 %T1.69897 A
3 %T1.52288 A
4 %T1.39794 A

Quick answers

Quick answers

How many %T is 1 A?
1 A is 10 %T.
How many %T is 10 A?
10 A is 1×10⁻⁸ %T.

The units

About these units

Absorbance (A)

The base-ten logarithm of what is blocked. Proportional to concentration.

Percent transmittance (%T)

How much light gets through, as a percentage.

Learn more about absorbance units

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