What's the weight of iron It's better to have a formula. And the density of iron

What's the weight of iron It's better to have a formula. And the density of iron

Weight calculation formula:
Weight = L x W x H x 7.8/1000
Among them: length, width and height are all measured in centimeters
The result is: kg
This problem lacks a thickness data
What is the density? You can find it in books or on the Internet,
For example, you can type iron density in Google
Or input: Steel density
Come and search, and you'll find it
The density of iron and steel is usually about the same
Generally: about 7.8, different steel, density has a slight difference, such as: possible density 7.83, 7.85, 7.86