Function bytes_si 

pub fn bytes_si(n: u64) -> String

Format a byte count with base-1000 SI decimal units (B, kB, MB, GB, TB, …), for anything stored or transferred (see the module docs). Memory uses bytes.

use tilo_ui::format::bytes_si;
assert_eq!(bytes_si(999), "999 B");
assert_eq!(bytes_si(1000), "1.0 kB");
assert_eq!(bytes_si(1_500_000), "1.5 MB");