How to Measure Mantels

Firebox Information

Determine your firebox type: (1) Masonry, (2) Non-vented, (3) Vented. If available, note the manufacturer and model number.

Three different types of fireboxes (masonry, non-vented, and vented)

(A) Firebox Opening Width

Measure the opening width of your firebox. Make sure to account for any vents, louvres, or access panels that cannot be covered.

(B) Firebox Opening Height

Measure the opening height of your firebox. Make sure to account for any vents, louvres, or access panels that cannot be covered.

(C) Distance from Opening to Floor

Measure the distance from the bottom of your firebox opening to the floor. Make sure to note if this measurement is from the finished flooring or the sub floor if flooring is not yet installed.

(D) Firebox Mounting Height (Non-Masonry Fireboxes Only)

Measure the distance from the bottom of the firebox chassis to the floor. Again, make sure to note if this measurement is from the finished flooring or the sub floor.

Diagram of measurements A, E, F, G, and H needed for cast stone fireplace mantels

(E) Available Wall Space on Left

Measure from the left side of your firebox opening to the first wall obstruction (gas valve, window, door, change in wall depth, etc).

(F) Available Wall Space on Right

Measure from the right side of your firebox opening to the first wall obstruction (gas valve, window, door, change in wall depth, etc).

(G) Ceiling Height

Measure from the floor to the start of your ceiling. This will be used to determine the appropriate finish height of your mantel and the size of overmantel options.

(H) Total Wall Space

Measure the total flat wall space. This measurement should be equal to the sum of measurements A, E and F.