Follow the steps below to create a formula field that will give you the 18 characters ID of the records.
1. Go to Setup | Customize | object name | click Fields - For Custom objects: Setup | Create | Objects | object name 3. In the related list "Custom Fields & Relationships" click New. 4. Click the Formula radio button. 5. Click the Text radio button for "Formula Return Type." 6. Input the following Formula into the Formula Editor: CASESAFEID(Id) 7. Set Field Visibility, add/ remove from Page Layout(s). 8. Click Save.
Use can use Salesforce 15 to 18 digit ID converter, convert the whole list of 15 digit ID you want and copy-paste in the excel. The order of the result will be the same in which you have provided the 15 digit IDs. Salesforce 15-to18 digit ID converter (https://sfdcwisdom.com/salesforce-15-to-18-digit)
If you want to do ad-hoc conversions of Id's, rather than programatically, then this Chrome extension makes it easy: https://chrome.google.com/webstore/detail/sf-15-to-18/cogllpmaoflgaekieefhmglbpgdgmoeg
FYI - I'm the developer. Please use the feedback form on the app if you'd like to suggest any improvements or additional functionality.
1) https://developer.salesforce.com/forums/?id=906F0000000BQGnIAO
2)
Convert a 15 character ID to a 18 character ID
1) https://help.salesforce.com/apex/HTViewSolution?id=000005288&language=en_US
Follow the steps below to create a formula field that will give you the 18 characters ID of the records.
1. Go to Setup | Customize | object name | click Fields
- For Custom objects: Setup | Create | Objects | object name
3. In the related list "Custom Fields & Relationships" click New.
4. Click the Formula radio button.
5. Click the Text radio button for "Formula Return Type."
6. Input the following Formula into the Formula Editor:
CASESAFEID(Id)
7. Set Field Visibility, add/ remove from Page Layout(s).
8. Click Save.
Let us know if this will help you
https://chrome.google.com/webstore/detail/sf-15-to-18/cogllpmaoflgaekieefhmglbpgdgmoeg
FYI - I'm the developer. Please use the feedback form on the app if you'd like to suggest any improvements or additional functionality.
Thanks!