Login to Gmail
You will have to first be logged in to your gmail in order to delete your gmail account. At the time of writing, we are only able to find the delete function on the web browser. You can login to any web browser to access the function to delete your Gmail account.
Go to Google account
Next you will have to go to Google account. This button is located at the top right corner of your gmail screen. Click on the button to access the settings for your account.
Data & personalization
Once you have clicked Account. Scroll down and look for Data & personalization access.
Once you click Data & personalization, u will have the option to download your data and delete service or your account. You can download a copy of your data in case you need it, basically all your data will be gone forever if you delete your account. Click the option Delete a service.
You can choose to delete any Google related services or delete your full Google account from this point. There is also option where you can deactivate your account instead of permanently deleting it
Delete your Google Account
You will now have the option to Delete your account
On the next page is the final conformation where you delete your account. Do read the terms and conditions. Click yes to acknowledge both buttons , Click delete my account.
You will also be prompted a final password request before your account is deleted. Enter your password to proceed.
You have the choice to delete or deactivate your gmail or google account. You also have the choice to deactivate any other Google services based on options.
Here is also a useful youtube guide on how to delete your gmail or any google related account.