Firepit Stone Calculator
Estimate the number of blocks or stones for building a fire pit.
Fire Pit Stone Calculator
1. Shape & Dimensions
2. Wall & Capstone Blocks
3. Safety & Cost
per brick
Live Project Visualizer
A top-down schematic of your firepit. Not to scale.
Building Your Fire Pit: A Guide to the Fire Pit Stone Calculator
A backyard fire pit is a fantastic DIY project, and our fire pit stone calculator is the perfect planning tool. It helps you estimate the number of wall blocks needed to create the circular wall and the amount of gravel required for a safe, stable base.
Safety is paramount when building a fire pit. You must use fire-rated materials like fire brick or concrete wall blocks specifically designed for this purpose. It's also crucial to have a 4-6 inch gravel base for drainage. This calculator ensures you can budget for and purchase all the necessary components for a safe and beautiful fire feature.
Frequently Asked Questions
How many blocks do I need for a 3-foot fire pit?
For a 3-foot inner diameter pit using standard 12-inch wide trapezoidal blocks, you'll typically need 12-14 blocks per layer (or course). The exact number depends on the block's specific shape.
Is it safe to use river rock or regular stones in a fire pit?
No, absolutely not. Stones from your yard, especially porous ones like river rock, can trap moisture. When heated, this moisture turns to steam and can cause the rock to explode violently. Only use fire-rated bricks or blocks.
What do I put at the bottom of a fire pit?
The base of your fire pit should be a 4-6 inch layer of compacted gravel for drainage, topped with a 1-2 inch layer of sand. Some people also place a layer of lava rock on top of the sand.
Do I need to use mortar for a fire pit kit?
Many modern fire pit kits feature interlocking blocks that don't require mortar. However, applying a bead of high-temperature construction adhesive between layers adds significant stability and is highly recommended.
What is a fire pit ring or insert?
A metal fire pit ring is an insert that sits inside your block wall. It protects the concrete blocks from direct, intense heat, which can cause them to degrade and crack over time. It significantly extends the life of your fire pit.
How big should a backyard fire pit be?
A good size for a typical backyard fire pit is between 3 and 4 feet in inner diameter. This provides enough space for a decent fire while allowing people to sit comfortably around it.