Here's a breakdown:
* When "at least" is followed by a list: You do need a comma after "at least".
* Example: "I need at least, a pencil, paper, and a calculator for this test."
* When "at least" is followed by a phrase or clause: You may or may not need a comma.
* Example: "I need at least two hours to complete this project." (No comma needed)
* Example: "I need at least, two hours, to complete this project, as it's quite complex." (Commas needed to separate the phrases)
* When "at least" is used as a single word modifier: You do not need a comma after it.
* Example: "I need at least two hours of sleep."
Key takeaway:
* Focus on the structure of your sentence and how you are using "at least". If it's followed by a list, a comma is needed. Otherwise, consider the flow of your sentence and whether a comma improves readability.