How to Count Number of Selected Options in a Multiple Select Field Using Formulas

[Charles_Turner]

I have a multiple select field with four options: 2020, 2021, 2022, 2023. 

I want a formula field that prints how many of these options were selected. 

I played a bit with Count and If statements, but couldn't get anything to function quite right. 

Any help appreciated! 

[Jack_Manuel]

You can use this formula from Airtable themselves.