Absorbance to percent absorbed
Type a value in A to get it in % absorbed instantly.
90% absorbed
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 % absorbed
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 = 90 % absorbed.
Every unit
Your absorbance in every unit
Tables
A to % absorbed conversion table
| A | % absorbed |
|---|---|
| 0.01 A | 2.27628 % absorbed |
| 0.05 A | 10.8749 % absorbed |
| 0.1 A | 20.5672 % absorbed |
| 0.3 A | 49.8813 % absorbed |
| 0.5 A | 68.3772 % absorbed |
| 0.7 A | 80.0474 % absorbed |
| 1 A | 90 % absorbed |
| 1.5 A | 96.8377 % absorbed |
| 2 A | 99 % absorbed |
| 3 A | 99.9 % absorbed |
| 4 A | 99.99 % absorbed |
% absorbed to A conversion table
| % absorbed | A |
|---|---|
| 0.01 % absorbed | 4.343×10⁻⁵ A |
| 0.05 % absorbed | 0.000217202 A |
| 0.1 % absorbed | 0.000434512 A |
| 0.3 % absorbed | 0.00130484 A |
| 0.5 % absorbed | 0.00217692 A |
| 0.7 % absorbed | 0.00305075 A |
| 1 % absorbed | 0.00436481 A |
| 1.5 % absorbed | 0.00656377 A |
| 2 % absorbed | 0.00877392 A |
| 3 % absorbed | 0.0132283 A |
| 4 % absorbed | 0.0177288 A |
Quick answers
Quick answers
- How many % absorbed is 1 A?
- 1 A is 90 % absorbed.
- How many % absorbed is 10 A?
- 10 A is 100 % absorbed.
The units
About these units
Absorbance (A)
The base-ten logarithm of what is blocked. Proportional to concentration.
Percent absorbed (% absorbed)
How much light is stopped rather than passed.
Keep going