Pat
When a curve meets a straight it is usually never a 45 degree
If there is a formula I never heard of one

Do a simple full scale layout and then use and adustable triangle
to get the angles

Good Luck,
George

"Pat" wrote in message
oups.com...
I have to replace the moulding on a door. The door has two quarter
lites at the top, and these lites are curved. I am curious how to
calculate the angle that the mitre would need to be.

Any ideas? Is there a rule of thumb?