40㎡ = 40.0 m² (431 sq ft · 12.1 坪)
From a Japanese listing
Tatami size varies by region — the same “6畳” can differ by 15%+. Listings legally must also show ㎡.
40㎡
🏠 A 2LDK — couple or small family.
㎡ is the legal size. 畳/坪 are traditional — always cross-check the ㎡ figure.