Hat Size Guide Please review the size charts below for your chosen hat. The Bush hat comes in sizes 58cm - 62cm. The Zambezi and Safari crushables come in Small to XXLarge and you can use the chart to determine your size. Barmah hats come in sizes depending on type. How to Measure Take a soft measuring tape and place it around the circumference of the head, slightly above the ears, approximately 1" above the brow. Crushable Zambezi and Safari Size Chart Barmah Leather Size Chart Barmah Canvas Size Chart International Size Chart