Lava Rock Calculator
Uses a lower planning density (~900 kg/m³) than dense gravel.
Reviewed by MaterialNeeded Editorial Team, Editorial review for field workflows and ordering assumptions.
Step 1: Units
Step 2
Enter project measurements
Use decimals if needed (e.g. 3.5).
Step 3
How to use this calculator
Bed footprint and depth for fire pits or planters.
What the math is doing
Volume from L×W×D; weight uses reduced density.
Frequently asked questions
Fire pits?
Follow manufacturer clearances.
Irrigation?
Avoid burying emitters.
Weed seed?
Use fabric under rock in beds.
Color fade?
Natural variation is normal.