Exhaust clamp size

Hi all ,
What size clamp do I need for the 1.8 freelander 2004 the part where the back box joins the rest of the exhaust mines popped out and the clamp bolts sheared off I’m not to sure how the clamps are measured to get the correct size
It looks just over 2 inch so was hoping the 57 mm will fit obviously don’t want get one that’s to slack and won’t tighten up
Thanks

Measure it, no calipers? cut a 57mm slot in a sheet of paper and try it.