The micron and the millimetre are both small measures of distance in the metric system. The micron is more commonly called the micrometer. The micron is equal to 0.000001 meters, while the millimetre equals 0.001 meters. This means that it takes 1,000 microns to equal 1mm. By knowing how to convert, you can compare lengths in the two units accurately.
Divide the number of microns by 1,000 to convert to millimetres. For example, if you have 294 microns, divide 294 by 1,000 to get 0.294mm.
Confirm your conversion by multiplying the number of microns by 0.001 to convert to millimetres. For the present example, multiply 294 by 0.001 to get 0.294mm.
Verify your answer with a microns-to-millimetres online conversion (see Resources). Enter the number of microns and press "Go."