In engineering, the mass of an object is usually taken to be the force on the object due to gravity.
Formula of mass is the mass of a compound calculated by adding the atomic masses of the elements given in the formula of the compound.
1 tonne = 1000 kilograms
1 tonne = 1000000 grams
1 tonne = 1000000000 milligrams
1 tonne = 1000000000000 micrograms
1 kilogram = 1000 grams
1 kilogram = 1000000 milligrams
1 kilogram = 1000000000 micrograms
1 gram = 1000 milligrams
1 gram = 1000000 micrograms
1 milligram = 1000 micrograms
1 tonne = 2204.62226 pounds
1 kilogram = 2.20462226 pounds
1 gram = 0.00220462226 pounds
etc ...