Fire Pit Calculator

How many blocks do I need for a fire pit?

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Order this much fire pit block

72blocks

Includes 5% extra. Plain landscape block can crack under heat, so use a steel ring or fire brick liner. The International Fire Code sets 25 ft from structures for recreational fires and a 3 ft fuel area, and local rules vary, so confirm with your fire department before building.

4 courses, 16 in tall36 in inside, 17 blocks per course
Blocks per course17
Courses4
Outside diameter48 in
Finished height16 in
Gravel pad, 4 in0.5 cu yd

Enter the inside diameter and block size to see block count, finished size and the gravel pad, with the clearance rules you need to check.

How it works

The block ring circumference is 3.14 × (inside diameter + block depth). Divide by block length and multiply by courses, plus 5%.

Before you order

  • Use a steel ring or fire brick liner, because plain landscape block can spall or crack.
  • Leave small gaps in the bottom course to let air feed the fire.
  • Set the first course on a level gravel pad so the ring stays true.

Common questions

How far should a fire pit be from a house?

The International Fire Code calls for 25 feet from structures for recreational fires. Your local fire department sets the rule that applies to you.

How big should a fire pit be?

Inside diameters around 36 inches are common, which also matches the 3 foot fuel area in the fire code definition of a recreational fire.