AirsoftCalc

Unit converter

FPS and m/s, joules, grains and grams, inches and millimetres.

Speed

Energy

Mass

Length

Distance

Temperature

Reading Japanese specs

Japanese manufacturers, shops and fields quote velocity in m/s, energy in joules, and distances in metres. A few anchors make the conversion automatic.

Common figureConvertedWhat it means
90 m/s295 fpsTypical Japanese AEG out of the box (0.81 J on 0.20 g)
0.98 J99 m/s / 324 fps on 0.20 gJapan's legal maximum
0.135 J37 m/s / 121 fps on 0.20 gLimit for guns sold to ages 10–17 in Japan
0.25 g3.86 grThe everyday BB weight in Japan
6.08 mm0.239 inStandard Japanese inner barrel bore
40 m44 ydA long engagement at a Japanese field

1 fps = 0.3048 m/s, 1 grain = 0.0648 g, 1 inch = 25.4 mm, 1 yard = 0.9144 m.