A metre constant is a value that represents a number of metres. One metre is equivalent to 400 units (represented as real numbers). A metre constant can be written as any integer or real number followed by the suffixes m or M.

Either the integer part or the fractional part may be omitted, but not both. Here are some examples of valid metre constants: 0.8m -10m 3m .5m +2.5m

One crate is roughly equivalent to 1 m³.