Take each actor one by one to a spot off to an area with space to move freely while measuring. Explain what measurement you are taking, how they need to move or stand, and where and how you plan to place the tape against them prior to taking each measurement.
Run the measuring tape around the head to get the hat measurement. The tape should be approximately 1 inch above the ears and level. Be as consistent as possible from actor to actor; hats almost always need to be tried on for size as each style sits differently on the head.
Place the measuring tape around the base of the neck with one to two fingers placed gently between the neck and tape to add enough room for comfort. Take a neck measurement for all males, and for females who may be playing male roles. This is the only measurement that should be taken in half-inch increments. Round all other measurements up to the nearest full inch.
Measure the chest area for all males. Ask the actor to lift his arm, wrap the tape around it and then have him lower his arms at rest over the tape. Take a bust measurement for all females in the same manner around the fullest part of the bust.
Take men's sleeve measurements with the arm held out to the front, slightly bent. Measure from the base of the back neck to the shoulder, down around the elbow, and to the wrist. A male who is 6 feet tall should have a sleeve measurement close to 32 to 34 inches, so re-measure if your measurements come out significantly high or low compared to this standard.
Wrap the tape measure around the waist at the narrowest point of each female. This should be at or above the navel. Leave two fingers under the measuring tape for comfort. Measure a high waist (at navel level) and a low waist (at the pants waistband) for men in the same manner.
Wrap the tape around the body at the widest part of the hips for each female. Compare this measurement to the waist measurement; be sure you are seeing an average of 8 to 12 inches difference between the two. If the amounts are closer, you've been measuring too low on the waist measurements and will need to review those.
Measure each man's inseam from the upper inside leg down to the location of the desired hem. Ask your designer where this should fall based on the era of the play. Instruct the actor to hold the end of the measuring tape in place on his upper inner thigh and hold the tape at the hem to read the measurement.
Ask the actor for their height and shoe size. Height is a necessary measurement for cross-checking the measurements at the rental shop or sewing room. Designers will use the height measurement to determine if the sleeve length and inseam were all measured correctly.