To measure the around Bust/Chest Measurement, you need to put the measuring tape 1 inch below the armpit of one to the other as shown in the reference image below.
Size Guide
How To Measure Your Body: Chest
Size – blue hours atelier
Sizing & measurement guide – Studio Minapop
Size Guide – SavvyVille Boutique
How to measure
How to Measure Yourself Accurately for the Perfect Fit
Womens Shoe Size Conversion - Shoe Size Chart
Size Chart Yours Clothing
What are Body Measurements and How Do You Figure Them Out?
Kohl's SO Girls' Size Chart
How to Measure Your Bra Size: Bra Size Charts, Band and Cup Measurement Guide
Size Guide – Tayle Label
Men's Clothing Size Chart
Men's Size Chart - How to Measure