as happy as a clam

American English - informal :
خیلی شاد و خوشحال
به عنوان مثال :
Although the job does not pay very well, she is as happy as a clam there

منابع

• https://www.ldoceonline.com/dictionary/as-happy-as-a-clam

خیلی راضی

شاد و شنگول
خوشحال و راضی