Take your actual body measurements as they are more accurate than measuring over your clothes or shoes.
Collar: Measure around the base of the neck where the collar sits.
Chest: Measure the chest at the fullest part, placing the tape close up under the arms.
Waist: Measure the natural waistline.
Inside Leg: Measure from the crotch to where your trouser is normally worn on the shoe.
Jacket Length: Measure from the centre back of your neck to your hemline. Then length measurement will vary depending on the style.
Feet: Use a ruler or tape measure to measure your foot (from the heel to the tip of your longest toe) Be sure to measure both feet. Many people have feet of different sizes. Fit to the larger of the two.
I bought this jacket 2 weeks ago but found it had snags in the material all the way up the back. I exchanged it for another but on the new one the zip in one of the pockets was broken and also had several very small holes in the material which i hadn't noticed when i first got it. Its a shame because it loks good, is light weight and was exactly what i was looking for. I may have just been unlucky! Go Outdoors refunded me my money without any issues.