What size do I buy for weight/height?
654193
I bought mine for a horse, but if you're buying for a human, this might help: http://www.wikihow.com/Choose-the-Correct-Size-Yoga-Ball
112277
That's what I am and I bought large, but could wear a medium. It depends on how you carry your weight... The waist band is super stretchy, but the seat and hips are not, so if you're bottom heavy go with the large, but if you're more even throughout, a medium will work. They run big and long, but cinch at the ankle or roll up. :)
174328
I recommend you buy the XXL. I bought the XXL for my husband who is 6' and 210 lbs. It fits well over other clothing, plenty of room. Hope that helps.
1795727
I'm 5'9", 200, and went for a Large. It's snug but has worked really well for the last couple of years for me. My wife is 5'9" and 140. She has a S and it fits her well.
300750
I would suggest a tall large. I am 5"10 and a regular large is perfect. Be safe rather than sorry go for the tall.
37378
Their size guide would suggest a medium. Depends on your build and comfort. I'm 5'4" & 140lbs, got a medium. They're very tight, I use them for heavy lifting sessions.
601504
Given that I have only bought one size, and I am a fully grown adult, it's difficult for me to recommend which one you should pick for your son. But, I did scan through the reviews to see which ones mention buying smaller sizes for their children. I came across a few that would at least come close to your son's statistics. The first one I found was bought for a 9 year old who was "Very tall" for her age, and they got her a medium. The reviewer said that if you buy a size perhaps slightly bigger than you were hoping for, the outfit comes with several straps that wrap around the waist and legs that can tighten it. (which I can confirm is true.) The only part that I've ever found to be loose is the upper chest region. I can't even seem to get that region to stay tucked in when I move around too much in the outfit. Also, another reviewer bought this for her 13 year old son who was 5'7 and 120 pounds and chose large. She said it was "a tad loose, but not too long." This is probably the example you were looking for, so listen carefully: Given the fact that you son is the same age as hers, and is both shorter and weighs less than her son, Medium might be a wiser choice - but remember I can't confirm that, I've never bought or tried any other side except for XL. At any rate, I think whether you pick medium or large everything will be fine. The medium might fit perfectly, and the large, if you decided to get that one, would at least be really comfortable, nonrestrictive to motor functions, and more importantly; he'd be able to continue using it as he ages and grows. So either decision you make I think you'll find good things about either of them. Hope I was of help.
303126
I am 6'2", and I have the standard size which fits great. There is still plenty of slack to either tighten it up or loosen. I would recommend the x-large based on your weight.
1652447
X large worked fine for my husband. He is 6 feet tall with broad shoulders and a medium build. Hope that helps.
1720817
Man.......I'm only 5'3" and 163lbs and I go with the medium, they're some fitting charts on line that might be able to help you, good luck...
313694
If you look in the description it gives you measurements. I am 4'10 and 100 lbs. I bought a small.
130633
I am 5'6'' and Small/Medium size works just fine. In my opinion, the best approach is to go to a local outfitter store, they might have a special measuring device from Osprey. That what I did.
289265
Go to their website and put in your measurements. It will tell you what size is right for you.
392371
I think I got my size from the chart on the website. It showed what size would fit for the particular weight and height and it worked for me.
669253
Go with a Medium or Large. I ordered an XL based on another review, and it was just wrong. I'm 5'11" 185 and the XL was way too big for me.
122836
GreetingsI am 5 feet 7 inches and 180lbs it the large works for me. With your height large might work. Maybe
1799882
I'm 5'10" and a 32" waistline and I got a medium, they fit great. So I would say a medium would work for you also.