What is the proper abbreviation for 'seconds'?

Answer 1

Although many people use 'secs' as the abbreviation, according to the rules of the metric system, the correct abbreviation is simply a lower-case 's' for second or seconds, e.g.

10s

30s

1s

0.023s

(Using an apostrophe in any of the above examples is incorrect.)

In everyday writing, use these instead:

10 seconds

30 seconds

one second or 1 second

0.023 seconds or 23 thousandths of a second

Examples of when it's okay to use "s" for seconds:

m/s = meters per seconds

ms = milliseconds

mg/kg/s = milligrams per kilogram per second

u/s = units per second

Answer 2

The correct way to write seconds as a unit is with a lowercase 's'. Not a capital letter 's' and NOT as 'sec'.