Customary Units

Physical QuantityNameSymbolExpressed in SI Base Units
temperaturedegree Celsius°CK; an interval of 1°C = an interval of 1 K; 0°C = 273.15 K
volumelitrel, l, or L10-3 m3 (1 dm3)
masstonnet103 kg
areahectareha104 m2
timeminutemin60 s
timehourh3600 s
timedayd86 400 s
timecalendar yeara365.25 d; 31 557 600 s
arcdegree of arc°Π/180 rad
arcminute of arc'Π/10 800 rad
arcsecond of arc"Π/648 800 rad