Things You'll Need

Instructions

1

Measure or find out the absorbance value for your sample. For example, the spectrophotometer indicates your sample's absorbance is 0.532.
2

Multiply the absorbance by -1 to calculate the negative value. In this example, the negative absorbance is 0.532 x (-1) = -0.532.
3

Raise 10 to the power of the negative absorbance. In this example, 10^(-0.532) = 0.2938.
4

Multiply the result from the last step by 100 to calculate the percent transmittance. In this example, the percent transmittance is 0.2938 x 100 = 29.38 percent.