Depending on your cooking temperature, chicken legs take 40 to 50 minutes when cooking in an oven at 350 degrees Fahrenheit. If you are baking them in a Crock-Pot it can take 4 hours on high or up to 6 to 8 hours on low.
1 Additional Answer
If you're baking chicken legs at 400 degrees, then it should only take 20 to 25 minutes. Check them by cutting the thickest part and making sure it isn't pink.