Joule Chart for Airsoft Weapon Compliance
This Joule chart will be used at all of Airsoft-HQ games.
No non-compliant weapons will be allowed onto the field of play.
Joules and FPS: What is the relationship?
Many people have asked about the relationship between Joules and Feet Per Second (FPS). The mathematical formula for relating Joules to FPS (Velocity) is as follows:
0.5 x MASS (Kg) x (VELOCITY (meters / sec) ) ^ 2
Before plugging your numbers into the formula, you must ensure the following:
1. The weight of the BB is entered in kilograms. For example, a 0.2g BB equates to 0.0002 Kg.
2. The velocity is in meters per second, where one meter equals 3.3 feet. So 30 meters per second equates to 99 feet per second
The above table maps energy (joules) to FPS (feet per second) for a 0.2g up to 0.5g BBs. Note that all energy numbers in joules on our site are based on speeds of firing a BB at the weight specified. Obviously, use of heavier BBs will increase the MASS parameter and result in lower FPS as per the formula above.
On our field we will only chrono using 0.2g, 0.25g, and 0.28g BB's. If higher BB's are used the chrono will measure as a 0.28g BB.