You will need to take measurements with a measuring tape. Stand upright, without tension, just like you normaly stand in real life.
A - Height
When measuring height, you should stand with your back against a flat wall. There should be no socks or shoes on your feet. Heels and toes should be kept together, there should be no distance between the legs. Your heels, buttocks, shoulder blades, and the top of your head should be touching the wall. Keep your shoulders straight and your neck straight. Look straight ahead.
B - Chest
When measuring the girth of the chest, the tape should fit snugly to the body, pass from the front along the most prominent points, from the side through the armpits, clasping the shoulder blades from behind.
C - Waist
The waist is measured strictly horizontally along the narrowest part of the body, passing through the most prominent point of the abdomen.
D - Hips
When measuring the hips, the tape should be horizontal, passing through the middle of the thigh and behind along the most prominent points of the buttocks.
F - Inseam
The inseam is measured on the inside of the thigh. Start measuring from the junction of the leg to the torso (in the groin area) to the desired length of the pants.