Calculating nutrition value for riblets

Hello. I have lloked through most of the posting and have not found an answer yet so reaching out to others.
My question is how do you figure out calories on some of your dishes you make at home. Especially meats. I baked 2 riblets(just seasoning) with bones but no sauce yesterday. I eat one of them for dinner. My problem is I don't know how many calories it is. Or how to enter it into my food diary. Any suggestions. I have looked everywhere for help. :flowerforyou: