tonne

Name	Symbol	Quantity	SI units
tonne	t	mass	10³ kg
The tonne, symbol t, is a non-SI unit of mass accepted for use with the SI. One tonne is equal to 1000 kilograms, or 1 megagram, symbol Mg.
Definition			h c^-2 Δν_Cs
$1 \mspace{4mu} \text{t} \mspace{6mu} = \dfrac{(10^3) (299 \mspace{4mu} 792 \mspace{4mu} 458)^2}{(6.626 \mspace{4mu} 070 \mspace{4mu} 15 \times 10^{-34})(9 \mspace{4mu} 192 \mspace{4mu} 631 \mspace{4mu} 770)} \mspace{6mu} \dfrac{h \mspace{4mu} \Delta \nu _{Cs}}{c^2}\\ \\ \\ 1 \mspace{4mu} \text{t} \mspace{6mu} \approx 1.475 \mspace{4mu} 521 \mspace{4mu} 399 \mspace{4mu} 735 \mspace{4mu} 270 \mspace{4mu} 916 \times10^{43} \mspace{6mu} h \mspace{4mu} c^{-2} \mspace{4mu} \Delta \nu _{Cs}$

For everyday use, one cubic metre of water has a mass of one tonne.

The tonne is the unit of mass used on international standard road traffic signs.

The symbol T is the SI symbol for the tesla, and should not be used as a symbol for tonne.

The symbol for tonne, t, should always be on the line, e.g. 7.5 t, and not written as a superscript.