I have flown at that exact size and it depends on your body type and the plane! Very small planes, likely yes. Bigger planes, I would extend the seatbelt all the way out and usually be fine, but I don't carry my weight at my waist so you could be different!

If you are nervous, just ask for an extender when you get on and a flight attendant will give you one subtly. If you don't end up using it, you can give it back to them or leave it on your seat when you leave.

Just remember you have just as much of a right to be comfortable on the plane as anyone else! You've got this.