Unit Conversion & Lookup Matrix
Lava Rock Calculator & Volume Estimator
Estimate lightweight porous volcanic rock (red and black lava rock) for fire pits, succulent landscaping, and planters.
📐 Mathematical Conversion Formula:
Density ≈ 1,200 lbs/yd³ (0.60 tons/yd³) – approx. half the weight of quartz gravel Reference Conversion Table & Examples
Calculations are based on standard quarry aggregate testing weights at ambient moisture levels.
| Project Area & Depth | Volume (Cu Yds) | Weight (Tons) | Estimated 0.5 cu ft Bags | Application |
|---|---|---|---|---|
| 100 sq ft @ 2" depth | 0.62 cu yds | 0.37 Tons | 34 Bags | Fire pit surround |
| 200 sq ft @ 3" depth | 1.85 cu yds | 1.11 Tons | 100 Bags | Cactus garden bed |
Standard Density Factors by Aggregate Type
Use these verified density constants to perform custom volume-to-weight conversions:
| Aggregate Material | Density (lbs/cu yd) | Tons per Cu Yd | Tons to Yds Multiplier |
|---|---|---|---|
| Pea Gravel (3/8") | 2800 lbs/yd³ | 1.4 t/yd³ | 0.71 yds/ton |
| Crushed Stone #57 (1/2" - 1") | 2700 lbs/yd³ | 1.35 t/yd³ | 0.74 yds/ton |
| Crusher Run / Dense Grade (DGA) | 3000 lbs/yd³ | 1.5 t/yd³ | 0.67 yds/ton |
| River Rock (1" - 3") | 2600 lbs/yd³ | 1.3 t/yd³ | 0.77 yds/ton |
| Decomposed Granite (DG) | 3000 lbs/yd³ | 1.5 t/yd³ | 0.67 yds/ton |
| Drain Rock / Drainage Gravel (1" - 1.5") | 2600 lbs/yd³ | 1.3 t/yd³ | 0.77 yds/ton |
| Lava Rock (Red / Black) | 1200 lbs/yd³ | 0.6 t/yd³ | 1.67 yds/ton |
Frequently Asked Questions About Lava Rock Calculator
How much does a yard of lava rock weigh?
One cubic yard of lava rock weighs only about 1,200 lbs (0.6 tons), compared to 2,700-2,800 lbs for pea gravel or limestone.
Is lava rock safe for gas fire pit tables?
Yes, porous lava rock is naturally heat-resistant, does not explode under high heat when dry, and diffuses gas flames beautifully.
Missing a Stone Type or Have Feedback?
We update density presets and formulas regularly based on local quarry feedback.