An excerpt from http://bestfightinggear.com/how-to-choose-the-best-boxing-gloves/
Boxing Glove size is displayed as ounce or oz. The most common sizes available are 8 oz, 10 oz, 12 oz, 14 oz and 16 oz. There are no odd sizes (9 oz, 11 oz, 13 oz, and so on). It is worth noting that glove size and glove weight are different. Sizing does correspond with the weight of the glove, but not all the time. This means buying gloves sized at 16 oz does not mean they weigh exactly 16 oz.
Sizes are classified to easily know what glove weight a boxer should train in. Glove weight is important because it has to fit your chosen method of use. For example, bigger gloves have more padding, in turn, offer better hand better protection. These are best if you hit the heavy bag, mitts and other boxing training aids. Another example is how professional boxers often train in heavier gloves. They want to get accustomed to the heavier gloves’ weight so their hands will be faster during fight night.
Below are general guidelines on what size of boxing gloves you should wear according to height and weight.
Commonly used for Sparring: 16 oz – regardless of weight (Sparring is a time for you AND your opponent to help develop each other's skills by practicing real boxing moves in a real boxing environment. It is not the time for both fighters to try and beat each other up. Having an opponent close up his defense and run from you will not develop your skills in the ring.)
Commonly used for Competition: 8 oz and 10 oz – regardless of weight
*sometimes it depends on match regulations. In most fights, these are the normal sizes used by professional boxers.
Now you know what size you’re going to get. But before buying the boxing gloves, you should first wear them with hand wraps on. If you don’t have hand wraps with you while shopping (like most people), get a roll of quarters in your palm and wear the boxing gloves.
You could also measure the circumference of your hand before going to the store. Here is a 30-second video by RINGSIDE on how to measure hand circumference:
- 6” – 7.5” circumference, 12oz
- 7.5” – 8.5” circumference, 14oz
- 8.5” – 9.5” circumference, 16oz
- 9.5” and above circumference, 18oz or 20oz
You know it’s the best boxing gloves size for you when it has snug fit, is comfortable to wear, with fingertips reaching the top of the glove, and it won’t take a lot of force to make a fist.
