1. Lift your arms out to the side. Relax and do not puff out your chest.

2. Measure around the widest part of your chest and ensure the tape goes under the armpits, before dropping the arms.

3. Ensure the tape also covers the widest part of the back and does not slip down at the back.

4. The tape should follow around the widest part and usually crosses just above the nipples.

5. Leave room for one finger between the chest and the tape (the tape should not restrict normal breathing).

6. Please double check as this is an important measurement.