A fire pit is one of those weekend projects that looks impressive but is really just stacking blocks in a circle. Get your block count, row count, and gravel estimate here before you head to the supply yard.
Fire Pit Size
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Block / Brick Dimensions
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Scenario: You're building a 4 ft inner diameter fire pit with 4-inch thick walls, 16 inches tall, using 12 x 4 inch blocks.
Result: Outer diameter is 4.67 ft. Circumference needs about 15 blocks per row. At 4 rows tall, that's 60 blocks total plus about 0.16 cubic yards of gravel for the base.
A 3-foot diameter pit that's 12 inches tall needs 30-40 landscape blocks or 80-100 standard bricks. A 4-foot pit bumps that to 45-60 blocks. Use fire-rated bricks for the inner ring if you burn wood regularly.
36-44 inch inner diameter. Big enough for a real fire, small enough to sit around. Leave at least 7 feet of clearance to any structure or tree branches.
If you'll burn wood regularly, yes. Fire bricks handle 2,000+ degrees F without cracking. Standard concrete blocks will crack and crumble after repeated heating. A cheaper alternative is a steel fire ring insert inside the decorative block wall, which shields the blocks from direct heat.
2-4 inches of gravel or lava rock for drainage. Never use river rocks or wet stones. They trap moisture and can explode from steam pressure when heated.
Want to learn more before you start your project?
Read the full guide →
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