Measuring the Tombstone Vent looks like a nightmare.
Here is a real shortcut that is more accurate.
The "opening size" is the preference when ordering to fill an existing hole.
The width can be taken across the opening in several places below the arch top.
Choose the smallest measure taken.
The height can only be measured up the center.
Now, this is what eliminates all other face measures.
Measure only the side legs up to where the arch starts.
Double check both and use the smaller measure.
Now, that was much simpler than trying to measure the partial circumference of the arch top.
And these 3 measures eliminates about 5 other measures if not measuring the side legs.
This method is very accurate.
This is called "opening size" measuring.
The new Tombstone Vent will be manufactured 1/4" less per side and dimension-ally.
This will allow for an easy fit and simple install.
Now for "tip to tip" measuring.
The width is acquired by hooking the measure tape on one side and measuring across.
The height is again only to the tallest point of the arch.
And the "side legs" are from the base to the beginning of the arch turning.
Tip to tip will make the vent the size ordered without reducing.
The only measure left is just a decision for the vent depth or thickness.
Let us know if we forgot to cover anything.
Text Message 901.281.2887