Fire Glass Calculator

What Is a Fire Glass Calculator?

A fire glass calculator estimates how much decorative fire glass you need to fill a fire pit or fireplace. Enter your pit shape, dimensions, fill depth, and glass type to get volume in cubic feet and weight in pounds or kilograms. Fire glass is sold by weight, so an accurate estimate helps you buy the right amount without overpaying.

How Fire Glass Volume and Weight Are Calculated

Fire glass fill volume depends on the surface area of your fire pit and how deep you want the glass layer:

$$ \text{Volume} = \text{Area} \times \text{Depth} $$

Weight is then found by multiplying volume by the density of your chosen glass type:

$$ \text{Weight} = \text{Volume} \times \text{Density} $$

Recycled fire glass has a density around 1.445 g/cm³, while reflective fire glass is slightly lighter at about 1.38 g/cm³. A typical 24-inch square fire pit filled 3 inches deep needs roughly 15 to 20 pounds of fire glass.

For other landscaping fill materials, try the Gravel Calculator or Crushed Stone Calculator.