Android - How can I check storage I have used on Google photos

How to find storage requirements of your free Google Photos:

1. got to https://takeout.google.com/
2. pick only Photos for download
3. select parameters of the archive
4. wait for the process to finish (you will also get email)

You will then see the size of the archive(s) before downloading. As a bonus, you have now complete backup of your Google Photos.

Check here: https://drive.google.com/settings/storage

There under "Total storage" you can see your used storage, and below when you click on "View details" you can see the details:

Storage details 

XX.XX GB used 
Drive   X GB 
Gmail   X GB 
Google Photos   X GB

It is available in google drive as well as from within the photos app.

Photos App

1. Open photos app.
2. From the side menu, tap on settings
3. Tap on Back up & sync
4. Here you'll find backup account details with the storage analytics.

---

Google Drive

1. Visit drive.google.com
2. Click on the gear symbol at the top right. That's the settings
3. Under settings you'll find storage which should give you a fair estimate on how much storage space you've used and how much is remaining

If you need a breakdown of which google app is using how much storage,

1. Visit drive.google.com
2. To the bottom left you'll have a notificiation that says - x GB / Y GB used.
3. Click on it and it gives you a breakdown where in you should be able to see how much data google photos is taking up.