The easiest way to check your credit limit is by logging into your credit card account. Usually, it will show on your account page your balance information page. It might also show as an amount you have left to spend.
For example, if your account says you have $600 left on your limit and your balance is $2,400, then you have a credit card limit of $3,000. If you can’t find the information on your account page, you can always find it on the information that was sent to you physically or electronically when you first got the card.