Start with the opening measurements, then choose a door made for your fireplace. This guide helps you record the dimensions to use with your chosen model’s measuring instructions.
Bring a tape measure and something to record your measurements. A photo of the full opening will help when you choose your doors.
Stand the tape across the very top of the firebox opening, just under the lintel (the steel or stone bar that spans the top). Press it flat against both side walls. Round to the nearest 1/8 inch.
Measure the fireplace opening, not the existing door frame.
Measure across the bottom of the opening at the hearth. Record both widths, even when they differ.
Keep both measurements. Your chosen model’s instructions determine the fit and any overlap.
Measure the opening height on the left, keeping the tape vertical. Note whether you measured from the hearth or firebox floor, and whether the lintel sits below or behind the front opening. Record to the nearest 1/8 inch.
A raised hearth or recessed lintel may need additional measurements. Use the guide for your chosen door.
Repeat on the right side using the same starting and ending points. Keep both heights and take a photo if the hearth slopes or the top of the opening is uneven.
Record any difference; do not add overlap or subtract clearance yourself.
For a prefab fireplace, start by recording the width of the front metal opening. Your fireplace brand and model are also needed to check door compatibility and the correct measuring points.
Note any tracks, lips, louvers or handles around the opening. A photo helps show these details.
Record the height of the front opening to the nearest 1/8 inch. Follow the measuring guide for your fireplace and chosen door; it may ask for additional dimensions around the metal face or louvers.
Have your fireplace brand, model and a clear photo ready when checking fit.
Enter the measurements above to see your opening summary. Finished door dimensions depend on the model and mounting style.
↓ Choose your door nextChoose a door for your fireplace type, then use its measuring instructions to confirm fit. Keep your original opening measurements; the required overlap or clearance varies by model.
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