Understanding IBO & IBO Standards

So what is an IBO and IBO Speed?  First IBO is the International Bowhunting Organization.  Let's first talk about the three main components of actual arrow speed: draw weight, draw length, and arrow mass. The higher the draw weight - the faster the arrow will shoot. The longer the draw length - the faster the arrow will shoot. And the lighter the arrow - the faster it will go.  So for the purposes of testing, a slick manufacturer could setup a particular model bow and establish their bow's advertised speed using an unrealistic 100 lb. draw weight, 32" draw length, and shoot an anorexic 250 grain arrow. Surely that combination would yield a blazing fast test speed but would not be a realistic representation.

To really compare two bows, the industry uses a type of evaluation that ensures the bows are evaluated as closely as possible.  Manufacturers typically rate their bows using the same IBO Standard. To get an accurate IBO Speed rating, manufacturers must test their bows under the same preset conditions: setting the bow for exactly 70 lb. Peak Draw Weight, exactly 30" Draw Length, and they must shoot a test arrow that weighs precisely 350 grains.  This levels the playing field on basic settings, so the differences in IBO scores reflect other design attributes (brace height, cam aggressive, bow efficiency, etc.).

The International Bowhunting Organization (IBO) sets a 5 grains per pound standard that's pretty simple to follow.  Arrow weight should never be less than 5X the bow's draw weight.  An example of this would be for a 70lb. bow should shoot no less than a 350 (5 x 70) grain arrow.

IBO Standard applies to many of the 3-D archery courses, thus you will see a large number of competitive archery shooters setup their target arrows to weigh exactly 5 grains per pound.  The end result is it allows them to stay within the standards but gives them the fastest speeds.  Bowhunters on the other hand typically like to have an arrow weight that is between 5 and 9 grains per pound giving greater penetration into the animal.  See our Arrow Shaft Selector Charts.  Below is an IBO Standard Chart that provides information on Minimum Allowable Arrow Weights.

IBO STANDARD: Minimum Allowable Arrow Weight - Includes Tip Weight
80# Bow 78# Bow 76# Bow 74# Bow 72# Bow 70# Bow 68# Bow 66# Bow	400 gr min. 390 gr min. 380 gr min. 370 gr min. 360 gr min. 350 gr min. 340 gr min. 330 gr min.	64# Bow 62# Bow 60# Bow 58# Bow 56# Bow 54# Bow 52# Bow 50# Bow	320 gr min. 310 gr min. 300 gr min. 290 gr min. 280 gr min. 270 gr min. 260 gr min. 250 gr min.	48# Bow 46# Bow 44# Bow 42# Bow 40# Bow 38# Bow 36# Bow 34# Bow	320 gr min. 310 gr min. 300 gr min. 290 gr min. 280 gr min. 270 gr min. 260 gr min. 250 gr min.

Weight:  If you're concerned about your finished arrow weight or your F.O.C. balance it's worth mentioning that your choice and size of fletching material will have a significant impact on both of those attributes.  Take a look at the chart below to see how much your fletching choice will add to your finished arrow.  Since all of that weight is going to be concentrated in the rear of the arrow, heavy fletching material means a you'll also need more tip weight to maintain a good F.O.C. balance.

Additional Articles

Archery Calculators

Bow-ology

Arrow-ology & Broadhead-ology

Understanding Kinetic Energy

Determining Your Draw Length

Determining Your Draw Weight

Understanding F.O.C. % (Front of Center)

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