How to Measure Your Fireplace for Gas Logs
Three measurements, two minutes — get the right log set the first time.
Watch: 90-second visual walkthrough
Three Measurements You Need
Use a tape measure inside the empty firebox (no logs, no grate). Round down to the nearest inch.
Front Width
Inside the firebox, measure left wall to right wall at the front opening.
Rear Width
Measure the back wall, left to right. Many fireboxes taper — back is narrower than front.
Depth
Front opening to back wall. The log set must fit with at least 1" clearance behind.
Opening Height
Top of the opening to the floor of the firebox. Verifies clearance for taller log stacks.
Get Your Recommended Log Set Size
Enter your firebox measurements — we'll show the right log size and link you to compatible sets.
Recommended Size: "
Pro Tips Before You Order
Subtract for clearance
Always pick a log size 1-2" smaller than your front width. The flames need room to breathe and you need room for grate clearance on each side.
Vented vs Ventless changes the math
Ventless requires a tighter firebox fit (and meets stricter BTU codes). Vented is more forgiving — flames vent up the chimney, no max-BTU concern.
Doubt? Free expert review
Every order includes a free Expert Fit Review before production. Email us a photo + your measurements; we verify before anything ships.
Common Questions
What if my fireplace isn't square?
Most fireboxes taper from front to back. Always measure both front AND rear widths — pick a log set sized for the SMALLER (rear) dimension to ensure clearance.
What's the smallest fireplace that fits gas logs?
Minimum interior firebox: 28" front width × 14" depth × 18" height. Anything smaller and the flames won't draft properly (vented) or you'll exceed BTU room ratings (ventless).
Can I install gas logs in a wood-burning fireplace?
Yes — vented gas logs work in any masonry or factory-built wood-burning fireplace with a working chimney/damper. Ventless requires a sealed/safety-certified firebox; check your fireplace manual.
Do I need a professional installer?
The log set itself is DIY (just place the logs in the manufacturer pattern). The gas line connection MUST be done by a licensed plumber/gas fitter for code + insurance. Expect $200-400 for the line connection.
Will gas logs damage my chimney?
No — vented gas logs run cooler than wood and produce less creosote. Annual chimney inspection still recommended. Ventless logs don't use the chimney at all.