How many gigs do I need to enable time machine?

[Crisis]

I never used this feature before. Now I want to try this and I'm about to make another partition on an external drive for that. My computer has a 256GB SSD, how many gigs do I need for the time machine backup partition?

 

[Feed Me]

Depending on how full your SSD is, I'd say around 300gb.

 

[Crisis]

Thanks, My SSD has about 80gb free space. I will try 300gb.