Density of granite in every unit
Granite is the reference rock most stone figures descend from. Solid, it runs 165–172 lb/ft³ (specific gravity 2.65–2.75); crushed, the voids bring a yard down to ordinary crushed-stone weights. The chart covers the forms it's actually bought in:
| Form | lb/ft³ | lb/yd³ | t/yd³ |
|---|---|---|---|
| Solid granite | 165–172 | ≈ 4,536 | ≈ 2.3 |
| Crushed granite (¾″) | 100–104 | 2,700–2,800 | 1.35–1.4 |
| Decomposed granite (DG) | ≈ 111 | ≈ 3,000 | ≈ 1.5 |
| Granite boulders (stacked) | ≈ 110–120 | ≈ 3,000–3,240 | 1.5–1.6 |
| Rock | lb/ft³ |
|---|---|
| Basalt / trap rock | 180–190 |
| Granite | 165–172 |
| Marble | 160–170 |
| Limestone | 150–170 |
| Sandstone | 140–150 |
| Concrete (for scale) | ≈ 150 |
Granite sits in the upper-middle of the building stones — heavier than limestone, marble and sandstone, lighter only than the volcanic basalt and trap rock quarried for the densest aggregate. That mid-heavy weight, paired with its hardness, is exactly why granite became the reference stone: hard enough to last, common enough to quarry everywhere, and predictable enough that estimators lean on its numbers for everything from countertops to boulder walls.
Solid, crushed, and decomposed granite
“The density of granite” is really several numbers, because the same rock is sold in forms that trap very different amounts of air. Which one you want depends on what you’re buying:
- Solid granite — 165–172 lb/ft³: the physical constant, for slab weight, boulders, and countertop work. Specific gravity 2.65–2.75.
- Crushed granite (¾″) — 2,700–2,800 lb/yd³: the voids between angular pieces bring a yard down to ordinary crushed-stone weight; priced on the stone calculator.
- Decomposed granite (DG) — ≈ 3,000 lb/yd³: weathered granite fines that compact tight; a path and driveway surface, heavier per yard than clean stone.
- Granite boulders — ≈ 3,000–3,240 lb/yd³ stacked: big stone with air gaps between; individual boulders weigh at the solid rate, roughly 168 lb per cubic foot.
How much does a granite slab weigh?
For countertops and cladding, weight per square foot is thickness times the solid density. The two standard slab thicknesses work out to:
| Thickness | Per ft² | 40 ft² run |
|---|---|---|
| 2 cm (¾″) | 11–13 lb | 440–520 lb |
| 3 cm (1¼″) | 17–19 lb | 680–760 lb |
A 3 cm kitchen’s worth of granite is 700-plus pounds, which is why islands need blocking and long spans need support: the number isn’t academic once it’s over your cabinets.
How to use granite density in an estimate
Buying crushed or decomposed granite by the ton? The bulk figures above are what the stone calculator and tonnage calculator apply — area × depth × density, rounded the way the quarry sells. Already know the volume? The cubic yards to tons converter turns it straight to weight. And for a boulder, volume × 168 lb/ft³ gets you a lift weight before you rent the equipment.
That last one catches people out. A granite boulder the size of a beach ball is already north of 700 lb, and a modest 3 ft landscape boulder runs well over a ton — so the density decides the machine, the footing and whether two people or a skid-steer place it. On a dry-stack wall the same figure sets how much stone a course carries and what the base below it has to bear.
How to figure a granite weight or order
- Decide which form you’re pricing — solid slab, crushed, DG, or boulders — and take its density from Table 1.
- Get the volume: area × depth for a bulk order, thickness × area for a slab, or length × width × height for a boulder.
- Multiply volume by density — cubic feet × lb/ft³, or cubic yards × lb/yd³ — for the weight.
- Convert to tons (÷ 2,000) for a bulk order, since the quarry sells crushed and DG by the ton.
- Round up the way the material is sold — ¼ ton for bulk stone — on the material’s calculator.
What moves the density
The solid figure is a narrow range; the bulk figures wander with real-world conditions:
- Mineral composition. Darker, iron- and mica-heavy granites sit at the top of the solid range; pale, quartz-rich ones lower.
- Gradation and compaction. How crushed granite packs — and how tightly DG is compacted — swings pounds per yard.
- Moisture. Wet crushed stone and DG weigh more; the quarry scale sees the water.
- “Granite” loosely used. Commercial “black granite” is often denser gabbro or basalt — check the real rock if the weight matters.
- The scale ticket. Bulk forms are estimating averages; the weighed load governs the invoice.
Granite density FAQ
What is the density of granite?
Solid granite runs 165–172 lb per cubic foot — a specific gravity of 2.65–2.75, or 2,650–2,750 kg/m³. Composition moves it a little: darker, mineral-heavy granites sit at the top of the range.
How much does a cubic foot of granite weigh?
About 168 lb for solid stone — the mid-range figure. A cubic yard of solid granite is therefore around 4,536 lb, or 2.3 short tons: heavier than concrete, which is mostly granite-family aggregate with lighter paste between.
How much does crushed granite weigh per yard?
About 2,700–2,800 lb (1.35–1.4 tons) per cubic yard — the voids between pieces drop it well below solid stone, in line with other crushed rock. Decomposed granite (DG) compacts denser, roughly 3,000 lb loose-measured per placed yard.
How much does a granite countertop weigh?
A standard 3 cm (1¼ in) slab weighs about 17–19 lb per square foot, so a 40 ft² kitchen run carries roughly 680–760 lb. Thinner 2 cm material runs 11–13 lb/ft²; check the cabinet run can take it before templating.
Is granite heavier than concrete?
Yes, solid to solid: granite at ~168 lb/ft³ against concrete at 150. By the cubic yard that is 4,536 lb versus 4,050 — which is why granite boulders always weigh more than they look like they should.
What is the specific gravity of granite?
About 2.65 to 2.75 — granite is 2.65 to 2.75 times as dense as water. Multiply by water's 62.4 lb/ft³ and you get the 165–172 lb/ft³ solid range; multiply by 1,000 and you get 2,650–2,750 kg/m³. Specific gravity is just density expressed against water, which is why the same three numbers keep reappearing in different units.
How much does decomposed granite weigh?
Decomposed granite (DG) runs about 3,000 lb per placed cubic yard — roughly 1.5 tons — heavier than clean crushed stone because the fines pack into the voids as it compacts. That is the figure to order a DG path or driveway surface by; buy it by the ton and spread it 2–3 in over a compacted base.
Sources and standards
The solid density is a measured physical property; the bulk figures are estimating averages:
- Standard engineering references: granite 165–172 lb/ft³ (2.65–2.75 specific gravity), the range used across materials handbooks.
- Estimating densities: ~2,700–2,800 lb/yd³ crushed and ~3,000 lb/yd³ DG, matched to the site-wide aggregate set.
- Slab practice: ~18 lb/ft² for 3 cm and ~12 for 2 cm, the fabricator’s rule for stone-run weight.
- The scale ticket: composition, gradation and moisture move bulk weight — the weighed load governs the invoice.