Yards, tons, and bags
Gravel Calculator
Figure out cubic yards and tons for pea gravel, crushed stone, and driveway mix. Work from a rectangle, a known area, or a circle, add extra runs if the job is not one shape, then optionally price bags or a bulk delivery.
Compaction and waste usually add 5–10%. Densities are bulk, not solid rock. Confirm with your supplier before placing a large order.
8.89 yd³ · 13.80 tons · $759
How to use
Start with the shape of each surface you want to cover. A straight driveway or walk is length times width. A fire pit ring or circular patio is a diameter. If you already know square footage from a landscape plan, switch that area to known area. Add another area when the job is not one rectangle — a driveway plus a parking pad, or a path that steps around a garden bed.
Set depth next. Decorative pea gravel on landscape fabric is often about 2 inches. Garden paths sit around 2–3 inches. A patio base is commonly 4 inches. A gravel driveway is usually 4–6 inches after compaction, more if the soil underneath is soft. Drainage stone around pipe is often 8–12 inches. Presets apply those starting depths to every area; change any one area if part of the job is thinner.
Choose a material so volume can be turned into tons. Pea gravel, crushed stone, driveway gravel, and limestone do not weigh the same per cubic foot. If a bag or quarry ticket lists density, type that number into the density field. Optional bag size and unit price turn the same result into bags to buy and a rough material cost.
Formulas
Volume is area times thickness. In US units the thickness must be in feet, so divide inches by 12:
cubic feet = area (sq ft) × (depth in inches ÷ 12) cubic yards = cubic feet ÷ 27 tons = (cubic feet × density lb/ft³) ÷ 2,000
A 40 by 12 foot driveway at 6 inches is 480 square feet. Depth in feet is 0.5, so the bed is 240 cubic feet, or about 8.9 cubic yards. Driveway gravel at 115 lb/ft³ weighs 27,600 lb, which is 13.8 tons — the number most suppliers want if they sell by weight.
Metric is the same idea: cubic meters equal square meters times depth in meters (centimeters ÷ 100). Results still include US tons because most North American yards sell by the ton. One cubic meter of stone at 1,600 kg/m³ is about 1.76 tons. Circle area is π times radius squared; enter diameter and the calculator halves it for you.
Measure area
Area = L × W
Area = π × (D ÷ 2)²
Set depth
Area × Depth = Volume
Material density comparison
Bulk density is how heavy a loose cubic foot is, including the air gaps. Wet stone and packed loads run heavier; very angular stone with lots of voids can run lighter. Use the middle of the range unless your supplier gives a number. Tons per cubic yard are this calculator’s default density × 27 ÷ 2,000 — the same formula as the results panel.
| Material | Typical lb/ft³ | Default lb/ft³ | Default kg/m³ | Tons / yd³ | Best for |
|---|---|---|---|---|---|
| Pea gravel | 100–110 lb/ft³ | 105 | 1682 | 1.42 | Smooth 3/8 in stones for paths, play areas, and decorative beds. |
| Crushed stone | 100–120 lb/ft³ | 110 | 1762 | 1.49 | Angular rock that locks together under compaction. |
| Driveway gravel | 110–125 lb/ft³ | 115 | 1842 | 1.55 | Graded mix for a gravel driveway base and surface. |
| Gravel fill | 105–125 lb/ft³ | 115 | 1842 | 1.55 | Utility fill for trenches, backfill, and around drain pipes. |
| Limestone | 90–100 lb/ft³ | 95 | 1522 | 1.28 | Lighter crushed limestone for patios and walkway bases. |
| River rock | 90–110 lb/ft³ | 100 | 1602 | 1.35 | Rounded decorative stone; a pile looks heavier than it weighs. |
| Decomposed granite | 100–110 lb/ft³ | 105 | 1682 | 1.42 | Fines pack into a firm path surface when moistened and rolled. |
| Lava rock | 40–60 lb/ft³ | 50 | 801 | 0.68 | Lightweight volcanic rock for xeriscape beds and decorative cover. |
| Marble chips | 90–105 lb/ft³ | 95 | 1522 | 1.28 | White decorative chips for planting beds, borders, and accent color. |
Pea gravel jobs are usually thin. Two inches over fabric hides soil and stays raked; three inches is more comfortable underfoot on a path. Because the stones are round, they migrate on slopes and under tires, so pea gravel is a poor surface for a driveway. The pea gravel calculator carries the per-project depths, coverage per ton, and bag-vs-bulk math for small rounded stone.
Driveways want angular crushed stone or a graded mix that locks when compacted. Four inches is enough only on a well-built base with light cars. Six inches is a safer default for a new residential driveway. Heavy vehicles, clay soil, or freeze–thaw weather may need a deeper layer underneath the visible stone.
A cubic yard of 115 lb/ft³ driveway gravel is about 1.55 tons. The same yard of limestone at 95 lb/ft³ is 1.28 tons. That is why two quotes for “a yard of stone” can differ even when the pile looks the same size. If the quarry sells by the ton, use the tons result. If they sell by the yard, you can ignore weight except as a truck-limit check.
Recommended gravel depth
Depth is the number that moves the order the most. These ranges are starting points for driveways, paths, patios, and drainage trenches. Presets in the calculator apply the middle of each common job: 2 in decorative, 2.5 in path, 4 in patio, 6 in driveway, 10 in drainage.
Decorative vs path vs driveway depth
| Use | Typical depth | Metric | Notes |
|---|---|---|---|
| Decorative bed / border | 2 in | 5 cm | Over landscape fabric; hides soil without a deep pile. |
| Path / walkway | 2–3 in | 5–8 cm | Comfortable underfoot; add an edge so round stone stays put. |
| Patio (loose cover or paver base) | 3–4 in | 8–10 cm | Sitting areas. Compact crushed stone under pavers; looser stone on top can be thinner. |
| Driveway (passenger cars) | 4–6 in | 10–15 cm | Angular mix on a prepared base. Soft soil, freeze–thaw, or trucks need more. |
| Drainage trench | 8–12 in | 20–30 cm | Around perforated pipe; wrap fabric so soil does not wash in. |
Drainage stone is sized for gaps, not for walking. Ten inches around a perforated pipe is common; wrap fabric so soil does not wash into the stone. When you add that trench as a second area, keep driveway gravel and drainage stone on separate lines if their densities differ.
Order a little extra. Compaction, spilled edges, and uneven ground typically take 5–10% more than the volume from your measurements. Bags make sense under a cubic yard; beyond that, a bulk yard or ton delivery almost always costs less. Use the optional price fields to compare a 50 lb bag run against a per-ton quote on the same cubic yards.
When you measure, record each rectangle separately instead of averaging a tapered driveway. A 12-foot-wide run that flares to 16 feet at the street is two areas, not one “about 14 foot” guess. Same for a circular turnaround off a straight drive: keep the rectangle and the circle on their own lines so depth and material can differ.
Area to volume lookup
If you already know square footage, read across from your area. Each cell is cubic yards and US short tons at 115 lb/ft³ — the same driveway-gravel density the calculator starts with. Switch the material preset to pea gravel for a lighter ton result; cubic yards stay the same because volume does not depend on density.
| Area (sq ft) | 2 inyd³ / tons | 3 inyd³ / tons | 4 inyd³ / tons | 6 inyd³ / tons |
|---|---|---|---|---|
| 50 | 0.31 yd³0.48 t | 0.46 yd³0.72 t | 0.62 yd³0.96 t | 0.93 yd³1.44 t |
| 100 | 0.62 yd³0.96 t | 0.93 yd³1.44 t | 1.23 yd³1.92 t | 1.85 yd³2.88 t |
| 200 | 1.23 yd³1.92 t | 1.85 yd³2.88 t | 2.47 yd³3.83 t | 3.70 yd³5.75 t |
| 400 | 2.47 yd³3.83 t | 3.70 yd³5.75 t | 4.94 yd³7.67 t | 7.41 yd³11.50 t |
| 500 | 3.09 yd³4.79 t | 4.63 yd³7.19 t | 6.17 yd³9.58 t | 9.26 yd³14.38 t |
| 1,000 | 6.17 yd³9.58 t | 9.26 yd³14.38 t | 12.35 yd³19.17 t | 18.52 yd³28.75 t |
A 200 sq ft path at 4 inches is 2.47 cubic yards and 3.83 tons at this density — the same numbers as a 20 by 10 foot rectangle in the formulas above. Double the depth and you double both cubic yards and tons. Double the area and you do the same. For a shape that is not in the table, type the measurements into the calculator; it uses these exact formulas without the display rounding until the result panel.
Need landscape rock for a bed, border, or xeriscape? Open the Rock calculator. Sizing a small rounded stone for a path, patio, dog run, or play area — with coverage per ton and a bags-vs-bulk check — belongs on the Pea gravel calculator. Rounded cobble for a dry creek belongs on the River rock calculator.