is the age gap too big?

i just wanted to know people's opinions on a 19 year old female dating a 26 year old guy? I really like this guy at my work who works in a different department but like i said he's 26. I had no idea at first because he's really young looking and so easy to get along with i thought he was 21/22. not entirely sure if he likes me back but we get on really well and joke around a lot. i'm not saying that we will end up dating but i do like him and idk whether it's a huge waste of my time?