How do you permanently delete your Facebook account? It's pretty easy. Facebook users can also deactivate their account for a temporary or delete it permanently.

1. How to Delete
Facebook Account?
Want to close Facebook account permanently? It’s the easiest way
to remove all the information you’ve posted on this social media.
Once you delete Facebook account, all your data will be lost after
30 days. So back up your data, if you need them in the future.

2. Delete Facebook Account using
Desktop
 Open Facebook.com from a browser and log in to your
account.

3.  Click on the menu (▼) on the upper right corner.
 Choose the option Settings from the drop-down
menu.

4.  Click on Your Facebook information from the left
sidebar menu.

5.  Select the option Deactivation and Deletion.

6.  Select Permanently Delete Account and click
on Continue to Account Deletion.

7.  In the next page, Choose Download Info, if you want to
download your photos post and other information. And
click Delete Account.

8.  Provide your password for the delete confirmation
and click Continue.

9.  Facebook will ask once again to confirm the
termination process, confirm it.

10. Congratulations!
The Facebook account deletion process is complete.
Facebook will erase all your data if you don’t log in to
your account within the 30 days of account deletion.

11. Close Facebook account
from the mobile app
You can terminate your Facebook account from the
mobile app as well.

12.  Open the Facebook app from your mobile device.
 Tap on the Facebook menu (≡).

13.  Select the option Settings & Privacy from the menu.
 Choose Settings from the extended menu.

14.  Scroll down and tap on Account ownership and
control under the heading Your Facebook information.
 Tap on Deactivation and deletion.
 Select the Delete account option and tap on Continue to
account deletion.
 Tap on Delete Account. You can download all your photos,
posts and other information by tapping Download info.
 Enter your password to confirm the account termination
process.

15. How to cancel
Facebook account
deletion?
If you change your mind after deleting the FB account, you
can recover it within 30 days.

16.  Go to Facebook.com or Facebook app login page.
 Log in with your username/email and password.
 Once you logged in, click on the Cancel
Deletion option.
After that, you will be back on Facebook without losing
any of your content.

17. How to backup
Facebook data?
Before deleting your account, you may want to back up your
Facebook data first. FB allows you to back up all your
information, posts, photos, video, friends, comments, stories, etc.

18.  Log in to FB account.
 Click on the menu (▼) and choose Settings.

19.  Open the option Your Facebook information from
the sidebar menu.

20.  Select Download Your Information.
 Choose date range, format, and media quality before downloading.
 By default, all your data is selected, if you don’t want to download
any information, deselect it.
 Click Create File and Facebook start to create a copy of your files to
download.
 Once your data file is ready for download, you will get a notification
saying ” Your Facebook information file is ready to download.”
 In the Download your information page, click Download.
 Enter your password again to commence the download.

21. Source :
https://howtodelete.org/how-to-delete-facebook-account/