Is my dog fat?

(My English is bad sry)

I met a woman during walk and she told me, my dog ​​is fat. But I don't think so. Regy is my first dog. So I have my doubts. He is not pure Jack Russell Terrier. Probably mix with some unknown village dog. IDK. Ive had him since he was a puppy.

He is 6 years old and weight is 6.6kg (14,5lb)

I'm interested in your opinion.