How Many Blocks or Pavers for a Fire Pit? 36 to 60 Inch Chart
For a round fire pit, divide the outside circumference of the ring by the length of one block. With standard 12 inch wall blocks, a 36 inch fire pit takes about 14 blocks per row, or 42 blocks for 3 rows (about 12 inches tall). The paver calculator works out the patio around it.
Blocks per row by fire pit size
For tapered wall blocks about 12 inches long on the face, 7 inches deep and 4 inches tall, laid in a circle. Inside diameter is the fire bowl; outside is the ring including the blocks.
| Inside diameter | Outside diameter | Blocks per row | 3 rows (12 in tall) | 4 rows (16 in tall) |
|---|---|---|---|---|
| 36 in | 50 in | 14 | 42 | 56 |
| 40 in | 54 in | 15 | 45 | 60 |
| 44 in | 58 in | 16 | 48 | 64 |
| 48 in | 62 in | 17 | 51 | 68 |
| 60 in | 74 in | 20 | 60 | 80 |
Block shapes vary, so lay out the first row dry before buying the rest. If the last gap doesn't fit a full block, widen or tighten the circle slightly rather than cutting.
Fire pit kits and steel rings
- Kits come with the exact block count and often a steel ring; they're the simplest option.
- A steel fire ring liner protects concrete blocks from cracking and sets the inside diameter. Buy it first and build the blocks around it.
- Use fire-rated blocks or firebrick for the inner face if you're not using a steel ring. Ordinary concrete blocks and river rock can crack or even pop when they get very hot.
Pavers for a circle patio around the pit
For a 36 inch pit, standard 4 × 8 inch pavers (4.5 per sq ft) with 15% extra for the curved cuts, and a 4 inch compacted gravel base.
| Patio diameter | Area to pave | 4 × 8 pavers | Base gravel |
|---|---|---|---|
| 10 ft | 65 sq ft | 336 | 1.3 tons |
| 12 ft | 99 sq ft | 515 | 2.0 tons |
| 14 ft | 140 sq ft | 727 | 2.8 tons |
| 16 ft | 187 sq ft | 970 | 3.7 tons |
| 20 ft | 301 sq ft | 1,556 | 6.0 tons |
A 12 to 16 ft circle gives room for a ring of chairs. Add about 1 inch of bedding sand under the pavers and polymeric sand for the joints.
Base for the pit itself
Dig out 6 inches inside and under the ring, fill with compacted gravel, and set the first row of blocks level. Leave the center as gravel rather than concrete so rain drains away.
Frequently asked questions
How many blocks do I need for a 36 inch fire pit?
About 14 standard 12 inch wall blocks per row, or 42 for a 3-row pit about 12 inches tall.
How many blocks for a 48 inch fire pit?
About 17 blocks per row, or 51 for 3 rows and 68 for 4 rows.
How many pavers for a 12 foot circle around a fire pit?
A 12 ft circle around a 36 inch pit has about 99 sq ft to pave: about 515 pavers of 4 × 8 inches with 15% extra for the curved cuts.
How big should a fire pit be?
Most backyard pits are 36 to 44 inches across inside, and 12 to 18 inches tall. Leave at least 7 ft of clear space around the fire for chairs, and keep it at least 10 ft from the house, fences and trees.