Fire Glass & Lava Rock Calculator
Designed by fire feature experts to help you order exactly what you need. no more, no less.
Whether you're building a backyard fire feature or managing multiple installations, knowing how much fire glass or lava rock you need shouldn't be a guessing game. This calculator delivers fast, accurate estimates—so you can plan smarter, buy confidently, and keep your projects moving.
Step 1: Choose Your Media
Just enter your fire pit’s dimensions and we’ll handle the math. You’ll get a personalized recommendation based on your setup—so you know exactly what to order.
Fire Glass Calculator
Most Popular Fire Glass Options
Best-Selling Lava Rock
Ready to Go? Let’s Get Your Project Started
Explore our most popular fire glass and lava rock—trusted in over 100,000 installs, available in a variety of sizes, finishes, and colors, and engineered to withstand extreme heat for both rugged base layers and refined, modern looks.
Why Use This Calculator?
Precision at Every Scale
Get exact quantities tailored to your fire feature—whether
you're working on a single unit or multiple jobs.
Smart Planning, Made Easy
Save time, reduce waste, and eliminate overages with clear,
reliable results.
Built for Performance
This tool was developed by fire pit experts who understand the
demands of both residential and commercial-grade installs.
Your Results, Your Next Step
Now that you’ve got your media volume, it’s time to choose premium products built for long-term performance and visual impact.
Why Choose American Fire Products?
From small backyard features to large-scale commercial projects, we help professionals and DIYers alike get the job done right.
✅ Exact estimates save time on the jobsite
✅ Trusted in 100,000+ installs across the U.S.
✅ Fast
shipping and U.S. support team
NOT SURE WHAT TO CHOOSE?
Compare Fire Glass vs Lava Rock: What’s Right for Your Project?
Understand the pros, cons, and best uses of each—so you can build with confidence
Frequently Asked Questions
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American Fire Glass®
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How much Fire Glass do I need for my fire feature?
Use our handy fire glass calculator to determine how much fire glass you or your clients will need for your fire feature.
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What is the difference between 10 pound bags of fire glass and 10 pound jars of fire glass?
The only difference is the packaging. The fire glass is the exact same. Jars are typically used to display in stores & bags are mostly used for shipping direct.
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What types of fuel can be used with American Fire Products?
Fire glass can be used with natural gas or propane.
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Can I use fire glass with my ceramic logs or lite stone balls?
Do not place anything above the fire glass, that traps more heat, and the glass can fuse to itself.
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Can I use recycled glass indoors?
Recycled Fire Pit Glass is for outdoor use only.
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What is the difference between Premium and Classic Fire Glass?
Premium and Reflective are the same thing, it is made from colored glass with a mirrored finish on one side of each piece. Classic Fire Glass is colored glass without a mirrored finish.
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Is the Luster Finish the same as the Premium Reflective?
Luster is different than premium/reflective, the luster coating resembles oil on water.
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What type of glass works best with propane?
¼” will work with propane, but we recommend larger sizes of fire glass due to propane being heavier than air and the larger pieces give the gas less resistance.
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Why Wash/Rinse with 50/50 White Vinegar and Water?
This will avoid water spots and helps to break down ‘soot’ residue.
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Do I cover the burner with fire glass?
YES, a burner should NEVER be used unless it is completely covered. A 1/4" diameter media base is strongly recommended to cover the burner before applying the final topping. The media should cover the burner by about 1/2" to 1" before the final topping is added. Our small lava rock works best. Operating a burner without proper coverage can cause warpage and possible permanent damage to the burner and burner pan. This will also void the warranty on the product.
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What type of fire features can I use fire glass in?
Fire glass is perfect for gas fire pits, fire tables, fireplaces, and fire bowls. Just make sure you're using it in a gas-only setup. Fire glass is not safe for wood-burning fires.
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Can I mix fire glass colors or types?
Yes! You can mix and match colors and sizes to create custom looks. Many customers use a base layer of a darker glass and top it with brighter accent colors for a dramatic effect.
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Will the color of the fire glass fade over time?
No. Our fire glass is made from tempered glass with color infused all the way through. It won’t fade, melt, or emit fumes, and comes with a lifetime guarantee.
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How often should I replace my fire glass?
Fire glass doesn’t wear out like wood or lava rock, but you may want to clean or top it off once or twice a year, especially if it’s exposed to outdoor elements.
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Lava Rocks, Lite Stones & Balls
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How much Lava Rock do I need for my fire feature?
Use our handy lava rock calculator to determine how much lava rock you or your clients will need for your fire feature.
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Can I use lava rock with fire glass?
Yes! using small lava rock as a base layer is very cost effective. We recommend using small lava rock as a base to completely cover the burner and then adding 2" of fire glass depth on top of that.
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How many lava rocks come in a 10 pound bag?
All our 10 pound bags of lava rocks are based off of weight and not quantity of rocks. The number of rocks will very slightly from bag to bag.
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How many tumbled lava stones come in a 10 pound bag?
All our 10 pound bags of tumbled lava stones are based off of weight and not quantity of stones. The number of stones will very slightly from bag to bag.
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What are your Lite Stones made of?
Lite Stones and Lite Stone Balls are made of a lightweight ceramic fiber material.
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What is the proper media base for lite stones and lite stone balls?
Use small black lava rock as a base to properly insulate the burner. The stones/balls can be placed on top and rest in the flames like a decorative topping. The firepit should be fully functional with just the lava rock.
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Can I use all Medium or XXL Lava for my firepit?
We recommend using a base layer of Small Black Lava to insulate the burner and then you can use the larger pieces as a decorative topping.
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Which tab should I use in your calculator for Tumbled Lava Stone?
Tumbled lava rocks have similar density to fire glass.
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Do I cover the burner with fire glass?
YES, a burner should NEVER be used unless it is completely covered. A 1/4" diameter media base is strongly recommended to cover the burner before applying the final topping. The media should cover the burner by about 1/2" to 1" before the final topping is added. Our small lava rock works best. Operating a burner without proper coverage can cause warpage and possible permanent damage to the burner and burner pan. This will also void the warranty on the product.
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Are these products safe for high heat?
Absolutely. All of our lava rocks, Lite Stones, and Lite Stone Balls are rated for use in fire pits and fireplaces. Just make sure they are completely dry before lighting to avoid any popping or cracking.
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Do I need to replace lava rock over time?
Yes. Lava rock can deteriorate after a few seasons due to weather and heat. Check it annually and replace as needed for best performance.
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Don't See Your Question Listed?
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Don’t see your question listed?
Please contact [email protected] or call 888-264-1017 and one of our representatives will gladly assist you.
Still Not Sure? Let’s Build It Together
Every fire feature is different—and that’s where we come in. Whether you’re designing for a backyard, resort, or rooftop, our team will help you get it right.