Years ago I worked with a developer who had a different methodology: 2x, then bump the unit of measure. Thus, 1 day -> 2 weeks; 2 weeks -> 4 months. It's been remarkably accurate over the past couple of decades.

Mine is to multiply by five. It’s pretty accurate.

8 weeks => 16 months, 2 months => 4 years

???

Doesn't seem consistent

> 2 months => 4 years

It's consistently correct.

Except if you are in sales. If so it's 1/2 of what the last person said, or optionally 2 weeks.