Number Gravel Calculator
Gravel is sold three ways — by the cubic yard, by the ton, and by the bag — and quoted one way while you measure another. Enter length, width and depth and get all three numbers plus what each route costs.
Density 1.4 tons/yd³ is typical crushed stone; pea gravel runs about 1.3, dense road base up to 1.6. Depth guide: 2–3 in for paths and top-ups, 4–6 in for driveway bases.
How it works
Volume first: length × width × depth (in feet) gives cubic feet; divide by 27 for cubic yards. Tons = cubic yards × density — weight is how bulk yards actually price and deliver gravel. Bags divide the cubic feet by the bag size (0.5 cu ft is the common hardware-store bag). Costs are shown for both routes, because bags win on tiny jobs and lose badly on big ones.
Formula & worked example
Formula: Volume = length × width × depth in feet. Cubic yards = cubic feet ÷ 27. Tons = cubic yards × density (about 1.4 tons per yard for crushed stone). Bags = cubic feet ÷ bag size (0.5 cu ft for the standard hardware-store bag).
Worked example: A 20 × 10 ft driveway area at 3 in deep is 50 cu ft: 1.85 cubic yards, 2.59 tons, or 100 bags. Bulk at $40 a yard costs about $74.07 — the same gravel in $5 bags would run $500.
When to use this
- You are topping up a driveway and the yard quotes by the ton while your tape measure works in feet and inches.
- A path or drainage bed needs a number before you decide between a bulk drop and a stack of bags.
- You are building a shed base and want the stone priced both ways on the same volume.
- A supplier's minimum delivery is one yard and you need to know whether your job even clears it.
How to use it, step by step
- Measure the length and width of the area in feet.
- Set the depth in inches for this layer — run the calculator once per layer on a layered driveway build.
- Adjust the density if your stone is not typical crushed rock.
- Enter your local bulk price per cubic yard and the bag price.
- Read yards, tons and bags together, and compare the two cost lines before choosing how it arrives.
What the inputs mean
| Input | What it is | Typical values |
|---|---|---|
| Length and width | The area being covered, in feet | Driveways, paths, shed bases, drainage strips |
| Depth | Loose depth of this layer, in inches | 2 to 3 in for paths and top-ups, 4 to 6 in for bases |
| Density | Weight of the stone per cubic yard | 1.4 tons typical crushed stone; about 1.3 pea gravel, up to 1.6 dense base |
| Bulk price | Price per cubic yard, before any delivery fee | $40 is the page default |
| Bag price | Price per standard 0.5 cu ft bag | $5 is the page default |
Another worked example
A 30 by 12 ft driveway section at 4 inches deep takes 120 cubic feet of stone: 4.44 cubic yards, weighing 6.22 tons at the standard 1.4 density. As a bulk load at $45 a yard that is $200. In 0.5 cu ft bags the same volume is 240 bags, and at $5.50 a bag the total is $1,320 — a $1,120 argument for the dump truck on anything driveway-sized.
Frequently asked questions
How much gravel for a 20 × 10 ft area, 3 inches deep?
That is 50 cubic feet: 1.85 cubic yards, about 2.59 tons at standard density, or 100 of the 0.5 cu ft bags. Bulk at $40 a yard costs about $74 — the same coverage in $5 bags runs $500, which is why bags are for patch jobs, not driveways.
How many tons are in a cubic yard of gravel?
About 1.4 tons for typical crushed stone — a cubic yard is 27 cubic feet of rock, and rock is heavy. Pea gravel is nearer 1.3 tons, dense graded base up to 1.6. When a supplier quotes by the ton, this conversion is the whole ballgame.
How deep should driveway gravel be?
In layers: 4–6 inches of large base stone, 2–3 of medium, 2–3 of fine top stone on a proper build — 8–12 inches total. This calculator works per layer; run it once for each with that layer’s depth.
How much extra should I order?
About 10% over the computed volume covers uneven ground, spillage and compaction. For a single delivery, rounding up is cheap insurance: a second small delivery usually costs more in fees than the extra half-yard would have.
🌱 Mulch for the beds next to it?
Same volume math, garden edition — cubic yards, 2 cu ft bags and cost.
What if my area is L-shaped or curved?
Break it into rectangles on paper — a main run plus the parking pad, or the path plus the widening at the gate — run the calculator for each with the same depth, and add the cubic yards and tons. For a curve, measure it as the rectangle it mostly fills and accept a small overage; gravel forgives surplus far better than a bare strip at the far end.
My bags are not 0.5 cu ft — how do I use the bag count?
The bag line in this calculator is built on the standard 0.5 cu ft hardware-store bag. If your bag is a different size, take the cubic feet figure from the results and divide it by your bag's cubic feet instead. The volume and tonnage do not change — only how many trips down the aisle they turn into.