How much space does a Time Machine backup require?

[bailmdb]

I have a 15" MBP with a 250GB HDD. I have about 150 gigs free, so obviously only 100 gigs are in use. So if I use my external HDD to backup to Time Machine, will I only need 100 gigs of it, or will Time Machine need the full 250GB for the backup? Appreciate the insight.

 

[miles01110]

It will do incremental backups of all the changed files and will take up as much space as you give it after a certain amount of time.

 

[GGJstudios]

How much space does Time Machine eat?
How much space do you really need for backing up data?

 

[newdeal]

...

It will use 100gb to backup and then as you add things it will add to the backup. In all you should probobly use a 500gb drive but it will take years to fill it with just backups.

 

[RichyB]

I don't suppose there is a way to be more specific in what you want time machine to back up i.e. documents and safari settings.

 

[johnnyturbouk]

i have around 50gb on my ssd and 110gb on my optibay hdd
my time machine is appox 165gb

i would also ensure that the external hdd u use is formatted to hfs+
and if you have media on there, to partition the hdd, with one, the remaining for media/personal files amd this partition is in fat32 so i can connect it via usb2 to my router

 

[Macsavvytech]

Initial backup is the amount of space used on your main drive, after that incremental backups, backup whatever has changed. I have found with ~30 GB of data on my main drive I can use ~85GB of my Time Machine partition of my external hard drive. I do have a habit of copying big files on and off my main drive very frequently and this is represented in my backups where I have some that have only backed up 10MB and some that have backed up 10GB.