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How Much Gravel Do I Need for a Fire Pit?
A fire pit needs a few inches of gravel in the base for drainage, plus a gravel apron around it if you want a finished seating area. Here is what to use and how much to buy.
Gravel in the fire-pit base
Put 4–6 inches (100–150 mm) of gravel in the bottom of the pit. It lets rain drain away and creates an air gap so the fire breathes. Use a heat-tolerant stone (see below), level it, and you are ready to burn.
A 3 ft (90 cm) diameter pit needs only about 0.1–0.15 yd³ — roughly 3–5 bags of 0.5 ft³ gravel — for a 5 inch base.
Which gravel is safe around fire?
Use dense, dry, angular crushed stone such as crushed granite, crushed limestone or lava rock. Avoid stones that trap moisture and can crack or pop when heated:
- Avoid river rock and pea gravel inside the pit — smooth, dense and often damp, they can heat unevenly and burst.
- Avoid sandstone, limestone cobbles and any wet stone directly in the fire for the same reason.
- Pea gravel is fine for the surrounding seating area, just not as the base under the flames.
Gravel for the seating area around it
A gravel apron around the pit gives a clean, non-flammable surface for chairs. Spread 2–3 inches (50–75 mm) of pea gravel or crushed stone over a compacted base.
| Circle around pit | Area | Gravel at 3" |
|---|---|---|
| 8 ft diameter | ≈ 50 ft² | ≈ 0.5 yd³ (≈ 0.7 t) |
| 10 ft diameter | ≈ 79 ft² | ≈ 0.7 yd³ (≈ 1.0 t) |
| 12 ft diameter | ≈ 113 ft² | ≈ 1.0 yd³ (≈ 1.5 t) |
Use the Pea Gravel Calculator for the seating area and the Gravel Coverage Calculator to check how far a tonne goes. For depth advice on paths and patios, see the gravel depth guide.
Frequently asked questions
How much gravel do I put in the bottom of a fire pit?
Add 4–6 inches (100–150 mm) of heat-tolerant crushed stone in the base for drainage and airflow. A 3 ft diameter pit only needs about 3–5 bags of 0.5 ft³ gravel for a 5 inch layer.
What gravel is safe for a fire pit?
Use dry, dense, angular crushed stone such as crushed granite, crushed limestone or lava rock. Avoid river rock and pea gravel inside the pit — they can trap moisture and crack or pop when heated.
Can you use pea gravel around a fire pit?
Yes, for the surrounding seating area pea gravel is fine and looks good. Just do not use smooth, dense pea gravel or river rock directly under the flames, where trapped moisture can make stones burst.
How much gravel for a fire pit seating area?
Spread 2–3 inches of gravel. A 10 ft diameter circle around the pit is about 79 ft² and needs roughly 0.7 cubic yards (about 1 tonne) of gravel at a 3 inch depth.
Disclaimer: This guide gives general estimates for planning. Actual gravel quantities, weights and prices vary with material type, particle size, moisture, compaction, supplier and your province. Costs are material-only ballparks in Canadian dollars and exclude labour, delivery and taxes unless stated. Always confirm quantities and prices with your local supplier.