it’s not that bad. could be way worse. and it would be hard to be less off. there isn’t that much room there.
normally i look at mistakes in powers of ten. (no need to be more precise when you’re looking at being a factor off of something.) so yours was only a factor 10 off. (then there’s 100, 1,000, and so on.)
in this system, you couldn’t be less off, or you’d be right (factor 1).