Construction

Fire Glass Calculator

Estimate fire glass for a fire pit or feature.

Surface area

Depth

Density (lb/ft³)

Calculated Output

Fire glass needed 33.333

Volume 0.3333

Formula: lbs = area × depth/12 × density

Step-by-Step Breakdown

1. Values used:

2. Surface area = 4

3. Depth = 1

4. Density = 100 lb/ft³

6. Fire glass needed = 33.333

7. Volume = 0.3333

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The math behind it

volume (ft³) = area × depth; weight = volume × density (~100 lb/ft³ for fire glass). A 2 in layer is typical.

4 ft², 2 in deep → ~67 lb.

Over the burner?

Keep glass shallow over the burner ports for proper flames.