A simple method to convert men's pants sizes to women's sizes involves subtracting 21 inches from the men's pants waist measurement. This means a size 34-inch men's pants equals a women's size 13.
Even after converting the waist measurement, the inseam measurement should not be changed because men's sizes run in terms of waist measurements. But women's clothing sizes are unrelated to actual body measurements, with sizes ranging from 0 to 24 or larger. Of course, this means that when one converts women's pants sizes to men's, one must add 21 inches to the women's pants size to get the men's waist measurement.