What is the real difference between the tilley ltm5 airflo and tilley ltm6 airflo hat?

Paul, Good morning. The difference is the brim lengths: LTM5 Approx. 3 3/4" Crown 3 1/4" Front Brim 3" Back Brim 2 1/4" Side Brims LTM6 Approx. 4 3/8" Crown 3 1/4" Front/Back Brim 2 1/2" Side Brim I hope this helps. -Michelle

how do calculate hat size

Take a tape measure (or a piece of string you can measure and mark against a ruler or yardstick). You measure around head: Place the string or tape around your head about 1/8" above your ear, across the mid-forehead, completely circling your head. Hold the tape firmly, but not too tightly. Basically you need to measure your head exactly where the hat will sit. If your measurement falls between sizes, choose the next largest size. Head Circumference Inches US Hat Size Metric Hat Size 21⅛ 6¾ 54 21½ 6⅞ 55 21⅞ 7 56 22¼ 7⅛ 57 22⅝ 7¼ 58 23 7⅜ 59 23½ 7½ 60 23⅞ 7⅝ 61 24¼ 7¾ 62 24⅝ 7⅞ 63 25 8 64 25½ 8⅛ 65

Is it possible to iron wrinkled brims?

Ironing would not be advisable. Better to moisten the brim and lay a weight on the wrinkled section and let this weight flatten the wrinkle as it dries.

What's the difference between ltm2 and ltm6

The difference is brim size and available colors. The LTM2 is about 3/8" wider in front and back, and about 3/4" wider on the sides. Also the LTM2 brim width is consistent all the way around I think and floppier than the LTM6. As for color, it looks like they no longer make the LTM2 in natural color (white/cream) with green under side of brim....only khaki. The LTM6 is available in a variety of colors ...natural/green under, blue, red, khaki, etc.