The biggest one I’ve ever seen pressed against a tape measure was my own at 13.25”… which is the Lutino Red Tiger in my Avatar… I’ve seen one or two that were a teeny bit bigger, but never on a tape…
I’d love to see some of these larger ones on a tape measure. I’m not saying I don’t believe ya, I’m just saying it’s nice to see claims confirmed…
 
I don’t have mine pressed on a tape, but here she is in a bucket on a scale…
 
I have three oscars. Two are 9". My largest one is 13.7".
He is a thin oscar. He always has been. This oscar though has some very interesting markings. I will get a better pic tomorrow so all can see. I just had this picture on hand. It was taken about 1 month ago. I was saying to someone else on my home fish forum that this fish is my oldest fish. He is 8 years old now. Though I got him at 7" so he is even older than that.
Take a looky:
My first O lived 10 years and was 16 inches when he passed away. Sorry no pictures that was long before I even had internet or a computer. lol
The one I have now is 8 inches. But not even a year old.