How can I back up data/contacts on my iPhone to iCloud?

How to back up your iPhone or iPad with iCloud

After you back up your iPhone or iPad, you have a copy of your information to use in case your device is ever replaced, lost, or damaged. You can back up your device manually, or turn on iCloud Backup to automatically keep your device backed up.

Back up manually

Automatically back up with iCloud Backup

Back up manually

1. Connect your device to a Wi-Fi network.
2. Go to Settings > [your name], and tap iCloud.
3. 
   
4. 
5. Tap iCloud Backup.
6. Tap Back Up Now. Stay connected to your Wi-Fi network until the process ends. Under Back Up Now, the date and time of your last backup is shown. If you get an alert that you don't have enough iCloud storage space to complete the backup, follow the onscreen steps to buy more iCloud storage.
7. 
   
8. 

Automatically back up with iCloud Backup

1. Go to Settings > [your name] > iCloud > iCloud Backup and make sure that Back Up This [Device] is turned on.
2. Connect your device to a power source.
3. Connect your device to a Wi-Fi network.
4. Make sure that your device's screen is locked.
5. If you get an alert that you don't have enough iCloud storage space to complete the backup, follow the onscreen steps to buy more iCloud storage.

pjm2481 wrote:

I am trying to back up data/contacts on my iphone to icloud - can anyone assist ?

Contacts aren't included in the backup as they are synced.

What does iCloud back up? - Apple Support

You cannot.

Contacts are not included in an iCloud backup, since they are either already synced with iCloud or are synced with a 3rd party email account.

If your contacts are in the iCloud folder in the Contacts App, they are by definition stored in iCloud already.

If they are in a 3rd party email account's folder, then they are stored there instead.