The Japan Meteorological Agency magnitude scale () is a seismic magnitude scale set by the Japan Meteorological Agency.
In Japan, for shallow (depth < 60 km) earthquakes within 600 km, the Japan Meteorological Agency (JMA) calculates a magnitude labeled MJMA, M<sub>JMA</sub>, or M<sub><kbd>J</kbd></sub>. (These should not be confused with moment magnitudes JMA calculates, which are labeled M<sub>w</sub>(JMA) or M<sup>(JMA)</sup>, nor with the Shindo intensity scale.) JMA magnitudes are based (as typical with local scales) on the maximum amplitude of the ground motion; they agree "rather well" with the seismic moment magnitude in the range of 4.5 to 7.5, but underestimate larger magnitudes.