Construction Calculator - Home and Layout

Fire Glass Calculator

Estimate decorative fire glass volume for round fire pits.

Reviewed: August 26, 2026

Calculate Fire Glass

For the Fire Glass Calculator, enter diameter, depth / height, waste allowance, material density, and glass price. It models a circular fire-feature layer, converts volume through the entered bulk density, and reports pounds, 10-pound bags, and optional material cost.

Construction measuring tools arranged beside a residential building project

Formula used

Pounds = π × (diameter ÷ 2)² × fill depth × bulk density × (1 + waste ÷ 100), with dimensions converted to feet

Fire Glass Calculator measurement plan showing Diameter inches, Depth / height inches, Waste allowance percent

Worked fire glass example

Fire Glass Calculator example: A 14.6-in circular area at 3 in deep is 0.2907 ft³ before allowance. At 100 lb/ft³ and 10% allowance, the estimate is 31.97 lb, rounded to 4 ten-pound bags.

Volume, density, and supplier units

Round to whole bags while following the appliance or burner manufacturer's media type and maximum-depth instructions.

Field conditions that change tonnage

Burner hardware displacement, noncircular pans, required media depth, mixed media, void space, and product-specific bag weight affect the order.

Questions specific to this calculation

Which fire-glass depth and density should I use?

Enter the inside diameter and intended fire-glass depth for a circular burner pan or decorative fill zone, then use the product's bulk pounds per cubic foot.