Mass

Input
	carats (metric) Earth masses grains grams hudredweights (long) hudredweights (short) kilograms [kg] ounces (avoirdupois) ounces (troy) pounds (avoirdupois) pounds (troy) Solar masses slugs (g-pounds) stones tons (UK or long) tons (US or short) tonnes
Output
	carats (metric) Earth masses grains grams hudredweights (long) hudredweights (short) kilograms [kg] ounces (avoirdupois) ounces (troy) pounds (avoirdupois) pounds (troy) Solar masses slugs (g-pounds) stones tons (UK or long) tons (US or short) tonnes

The SI unit for mass is the kilogram. UK and US use the Avoirdupois system of weights. The Troy system of weights is used for precious metals and gemstones.