Chest Circumference
Measure around the fullest part of your chest at nipple height, keeping the tape level across your back. It should sit snug, not tight, on a natural breath out.
Video demo: https://youtu.be/Jk9r3eDSlYw?si=MLdVZ9u98lzysdFT
Bicep & Lower Bicep
Measure around the bicep with your arm relaxed by your side. Keep the tape snug, not tight.
Thigh & Lower Thigh
Measure around the thigh with your leg relaxed, standing naturally. Keep the tape snug, not tight.
Waistband
Measure around your hips at the height you wear the waistband of a jockstrap. Keep the tape snug, not tight, and measure on a natural breath out.