Compound Bow - IBO Speed ​​and AMO Speed

This value is the first thing you see on many bow product introductions, such as IBO=305fps, etc. IBO is an industry standard for measuring the speed of arrows shot from a bow. This standard was developed by the International Bowhunting Organization, so it is called IBO speed.

The calculation method of IBO is the shooting speed of a 70-pound bow with a 30-inch draw length and a 350-grain (weight unit, English grains, 1 grain equals 0.065 grams, 350 grains is 22.75 grams) arrow.

The proportional relationship of this calculation method is that every pound of draw force pushes 5 grains of arrow weight (under the premise of not exceeding 80 pounds). In fact, the effect of draw length on speed can also be affected. Generally, the speed will increase by 5fps for every inch of draw length increase.

AMO speed is also the industry standard for calculating bow shooting speed. This standard was developed by the Archery Manufacturers Organization, so it is called AMO speed. This calculation method was very popular in the past. The calculation method of AMO speed is: the shooting speed of a 60-pound bow with a 540-grain (equal to 35.1 grams) arrow at a draw length of 30 inches.

The proportional relationship of this calculation method is that each pound of drawing force pushes 9 grains of arrow weight. This calculation method was popular in the past, but it is no longer used in advertising.