Always take measurements to determine the correct size for purchasing or tailoring raincoats. Raincoats are typically made several inches larger than your usual size to account for their lining and the clothing that will be worn underneath. Size charts can be found on the inside of catalogs, on websites and on the back of patterns for rain suits, raincoats and rain jackets. Check your measurements against the sizing chart to ensure the most accurate size and the best raincoat fit.
To get the chest measurement, which is usually the determining measurement for the raincoat's size, measure across the chest under the arms along the fullest part.
Measure from the neck to the wrist to get the sleeve length for the raincoat.
For the overall length, measure from the back of the neck (the collar area) to the point where you want the raincoat to fall.
Measure the waist for women's raincoats and raincoat patterns that will be tailored to accentuate the waist.