First I checked the sizing chart against the numbered sizing of my existing hats. Based on the corresponding numbers in the chart, I ordered a medium. It arrived a day earlier than expected, however, it was too big. I didn't feel that ordering the resizing strips would make a sufficient difference. I emailed a request for a return and two days later it was allowed. A prepaid USPS sticker was provided for printing out and placing on the original package. After a couple of days, I received an email that my PayPal would be credited as the return had been received. I then ordered a small. After receiving it I checked the fit and it was perfect. I live in a windy area and the hat sits well when others might blow off. I would prefer a little broader brim for shading. The material inside the hat helps keep the shape. Overall a well designed and attractive hat.