Cariello the right size mirror would line up with the firebox the fireplace surround or the inside or outside edges of the mantel if in doubt take news papers tape them together cut out a circle for each size that you are considering tape the news paper template over the fireplace with painters tape and you will see which size of mirror works best for you.
Mirror over fireplace height.
Hanging an oversize mirror above your fireplace adds sparkling drama to the room.
How to hang a large oversized mirror over the mantle.
We love the look of a rococo plaster or baroque gilt italian frame for a traditional interior.
For more modern spaces a large sunburst design could be an eye catching choice.
The dancing reflections can create illusions of grandeur.
There is an art to hanging artwork and mirrors.
However it s not rocket science and if you follow some basic guidelines you ll get it right every time.
The width of the mirror the reflective part only should be roughly the same as the width of the fireplace opening.
I have bought a corbel style shelf for above the fireplace 120cm in length v fireplace hole 85cm and a large mirror 100cm length and 130cm high.
It will all fit with about 10cm gap between mirror and shelf and 10cm gap between mirror and ceiling.
The mirror frame should not extend beyond the end of the mantelpiece shelf.