Chrono tool
FPS ↔ Joules calculator
Enter your chrono reading and BB weight to see energy and which common field classes you fit. Limits vary by field — always check the field's own rules.
BB weight
Energy
1.14 J
FPS @ 0.20g
350
FPS @ 0.20g equiv.
350
BB weight
0.20 g
Common class limits
CQB / indoor
LEGAL≤ 1.14 J · ≈350 FPS @ 0.20g
No minimum distance
Rifleman
LEGAL≤ 1.49 J · ≈400 FPS @ 0.20g
~20 ft minimum distance
DMR
LEGAL≤ 1.88 J · ≈450 FPS @ 0.20g
~50 ft minimum distance
Bolt-action sniper
LEGAL≤ 2.32 J · ≈500 FPS @ 0.20g
~100 ft minimum distance
Typical US limits shown for reference. Heavier BBs carry more energy at the same FPS, which is why many fields chrono in joules.