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Base gravel for the fire pit itself plus the surrounding seating area, sized for safe clearance.
With these inputs:
| Result | Value |
|---|---|
| Total gravel needed | 1.93 tons |
| Inside the pit | 0.14 yd³ / 0.2 tons |
| Surround ring | 1.28 yd³ / 1.73 tons |
| Estimated cost | $67 – $132 |
| Pit inside diameter | 3 ft |
| Pit floor area | 7 sq ft |
| Pit drainage stone — #57 Crushed Stone (3/4") | 6" · 0.14 yd³ |
| Finished surround diameter | 13 ft |
| Surround ring area | 126 sq ft |
| Surround stone — Pea Gravel | 3" · 1.28 yd³ |
| Total area | 133 sq ft |
| Edging for outer ring | 41 linear ft |
| Material cost | $67 – $132 |
Use washed #57 stone inside the pit — it drains and it will not trap water. Never use river rock, pea gravel, or any rounded, previously water-worn stone inside a fire pit: trapped moisture can turn to steam and make stones crack or burst.
Two separate quantities matter here: the drainage stone inside the pit, and the non-combustible gravel ring around it. This calculator sizes both, using the clearance distance that most codes and manufacturers call for.
Washed #57 crushed stone, four to six inches deep, for drainage. Avoid river rock and pea gravel inside the pit — rounded stone that has been water-worn can trap moisture and crack or pop when heated.
At least three feet of non-combustible surface in every direction, and five to seven feet if you want chairs on the gravel too. Check your local code and the pit manufacturer's spec.
Two to three inches over compacted base and landscape fabric is plenty for a seating surround.
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