Check the size of your Photos Library
Open Photos and choose Photos > Preferences > General. Click the Show in Finder button to go to your Photos Library. After Finder opens, select your Photos Library, then choose File > Get Info. Look under General to find the size.
The size of your Photos Library on your Mac will usually be slightly larger than the amount of space that you need to store your photos and videos in iCloud.*
See how much iCloud storage you're using
Choose Apple menu > System Preferences. Then select iCloud to view your total and available storage.
Add the size of your Photos Library to the amount of iCloud storage you're using
To store your current iCloud content and your Photos Library, you need an iCloud storage plan with enough space for both.
When you sign up for iCloud, you automatically get 5GB of free storage. You can upgrade your iCloud storage to a total of 50GB, 200GB, 1TB, or 2TB. You can also reduce the size of your Photos Library.
*There are several reasons the size of your Mac Photos Library might be larger than the amount of space needed to store your photos and videos:
- Your Photos Library might contain photos or videos that have already been added to iCloud Photo Library from another device.
- Part of your Photos Library size includes small system files. These files aren't uploaded when you turn on iCloud Photo Library.
- Your Mac and iCloud count the size of a GB differently. Your Mac displays storage representation in decimal, base 10 where 1 GB = 1,000,000,000 bytes. iCloud storage tiers are counted in binary, base 2 where 1 GB = 1, 073,741,824 bytes.