Die joule (J) is 'n energie-eenheid wat gebruik word om alle energie mee te meet. Dit is na die 19de-eeuse wetenskaplike James Prescott Joule vernoem. Die eenheidsstelling vir energie is E = F ⋅ x = m ⋅ a ⋅ x   = M ⋅ L T 2 ⋅ L = M ⋅ L 2 T 2 {\displaystyle E=F\cdot x=m\cdot a\cdot x\ =M\cdot {\frac {L}{T^{2}}}\cdot L={\frac {M\cdot L^{2}}{T^{2}}}} waar E is energie F is druk x is afstand m is massa M is massa (basiseenhgeid) L is lengte (basiseenheid) a is versnelling t is tyd T is tyd (basiseenheid) Dus is die basiseenheidsstelling vir die joule J = N ⋅ m = k g ⋅ m s 2 ⋅ m = k g ⋅ m 2 s 2 {\displaystyle {\rm {J=N\cdot m={\frac {kg\cdot m}{s^{2}}}\cdot m={}{\rm {\frac {kg\cdot m^{2}}{s^{2}}}}}}} Die joule is 'n betreklik klein energie-eenheid.