Wear a well-fitting, non-padded bra or measure over bare skin
Stand straight with arms relaxed at your sides
Keep the measuring tape level across your back and around the fullest part of your bust
Ensure the tape is snug but not tight and does not compress breast tissue
Measure the circumference in inches or centimeters
Record the measurement as your bust measurement
If measuring for fit, measure twice and use the larger value
If your tape is stretched or shifts, re-measure
If using a bra size method, repeat the process for your underbust measurement (tape under the bust, level and snug)