I have to change an entry door 80× 61.

Hire a licensed handyman or contractor to help you if you need it.

If you can't find the same size door, you may need to reframe the opening to accept the new door. You could try finding the door at Habitat Reuse store, etc. as it may be an older size.

A couple of details needed:

At this size, I'm assuming the door is actually a double door or a patio door...two doors in one frame?

Is 80x61 dimension the size of the door(s) or the size of the door and frame? If it's the door and frame size, it's easy enough for a competent carpenter to install a new set of doors at 80x60, which is a common size.

If it's the door size only you need to add the thickness of the frame to that. Then you need the rough opening (R.O.) size (the size of the hole in the wall when the door is taken out. This is designated as R.O. on the product label when you're shopping for doors.

As long as your new door R.O. requirement is less than the existing RO in your wall, you can pretty well install the closest door size available. Filling in a bit of extra space is not technically difficult. You may have to re-do some trim detail on the exterior and the interior after the door installation.

You won't unless someone ordered the wrong size, the exact size u need, that would be considered a special order door! Good luck, maybe a professional could figure it out!

Terri Whitteger gave an accurate description of how to measure a " door ". Did one a couple of weeks ago. May have to remove the trim to get tha actual size of the opening