What this guide works out, and what it does not
This page is about turning measurements you can take with a tape measure into a gravel order. It covers a surface layer: a walkway, a parking pad, a gravel patio seating area, or a decorative cover over landscape fabric. It also walks through the arithmetic that converts square feet into cubic yards and tons, so you can sanity-check any quote you are given.
What it does not do is decide your drainage, your subgrade, or how thick a layer your particular site needs. Those depend on soil, water movement and the loads the surface has to carry. Plan quantities here, then confirm anything structural with the person or the documentation that owns that decision.
Step 1: measure the surface you are covering
Measure the area that will actually receive gravel, and do it in sections. A driveway with a wider apron, a walkway that turns a corner and a planting bed that follows a curve are all easier to handle as two or three rectangles than as one optimistic guess at the whole shape. The calculator accepts multiple areas and adds them together.
- Measure at the level the gravel will sit on, not at the finished surface. A 3 in layer over a 4 in base means your tape sits on top of the base.
- Round each section up to the nearest half foot. Precision beyond that disappears into an order rounded to the nearest quarter cubic yard.
- Give any section you plan to fill deeper than the rest its own line, such as a low spot or a transition into a slope.
- For a tapered section, measure both ends and use the average width.
Step 2: choose a depth you can defend
Depth is the single biggest lever on the order. The calculator keeps planning ranges for common gravel uses and warns you when your number sits outside the range, but it never overrides your judgement: a thin decorative cover and a compactable base layer over the same area are completely different orders.
| Use case | Planning range | Default | Note |
|---|---|---|---|
| Walkway / path | 2–4 in | 3 in | Usually laid over a compacted base. |
| Gravel patio surface | 2–4 in | 3 in | Surface layer only; base is calculated separately. |
| General fill | 1–6 in | 3 in | Adjust depth to your project. |
Planning ranges, not site-specific specifications. Your soil, drainage and use can justify a different depth.
Two patterns are worth remembering. Loose surface layers usually get thinner as the stone gets larger, because bigger stone leaves more void space and stands proud of the ground with less height. Compactable layers are ordered a little thicker than the finished depth you want, because compaction removes air from the layer.
Step 3: convert square feet into cubic yards and tons
- Area × depth in inches ÷ 12This gives cubic feet. A 600 sq ft pad at 3 in is 600 × 3 ÷ 12 = 150 cubic feet.
- Cubic feet ÷ 2727 cubic feet make one cubic yard, the unit most bulk suppliers quote from. 150 ÷ 27 = 5.56 cubic yards.
- Add compaction and wasteCompaction applies only to layers that get compacted. Waste covers spillage, uneven ground, and the final wheelbarrow load you always seem to need.
- Convert to tons if the supplier sells by weightCubic yards × tons per cubic yard. This planner uses about 1.4 tons per cubic yard for gravel, but rock type, gradation and moisture change it, so ask for the supplier figure.
- Round the order upThe calculator rounds up to the nearest quarter cubic yard, which is the increment most bulk orders move in.
| Assumption | Planning value |
|---|---|
| Typical density | 1.4 tons/cu yd |
| Density range seen in practice | 1.2–1.7 tons/cu yd |
| Bag sizes used for bag estimates | 0.5 cu ft |
| Default waste allowance | 10% |
| Order rounding | Nearest 0.25 cu yd |
Crushed stone varies by rock type and size; limestone, granite and trap rock differ.
Two worked examples
Both examples below run the real calculation engine as this page renders, using the same defaults a first-time visitor sees in the calculator. Change the numbers in the calculator and you will reproduce them exactly.
Gravel surface layer for a 20 ft × 30 ft parking pad
A 20 ft × 30 ft pad gets a 3 in gravel surface layer over a base that is built and compacted separately, with the calculator default 10% waste allowance.
Inputs
- Material
- Gravel (crushed stone)
- Area
- 20 ft × 30 ft
- Depth
- 3 in
- Waste
- 10%
Results
- Project area
- 600 sq ft55.74 m²
- Depth used
- 3 in
- Volume before waste
- 150 cu ft5.56 cu yd
- Waste allowance
- 10%
- Volume to order
- 165 cu ft6.11 cu yd · 4.67 m³
- Order quantity
- 6.25 cu ydRounded up to the nearest 0.25 cu yd
- Estimated weight
- 8.56 tons7.76 tonnes at the 1.4 tons/cu yd planning density
- 0.5 cu ft bags
- 330 bags
- Bags or bulk?
- Bulk delivery is usually easier at this volume
- Truckloads
- 1 loads
| Depth | Volume to order | Order quantity | Estimated weight | Smallest bag size |
|---|---|---|---|---|
| 2 in | 4.07 cu yd | 4.25 cu yd | 5.7 tons | 220 bags |
| 3 in | 6.11 cu yd | 6.25 cu yd | 8.56 tons | 330 bags |
| 4 in | 8.15 cu yd | 8.25 cu yd | 11.41 tons | 440 bags |
Every column comes from the same calculation engine used by the calculator.
The depth comparison is the useful part of this result: the same pad at 2 in, 3 in and 4 in are three different orders, and the weight column shows how quickly a tonnage quote grows with depth. At this volume the calculator puts the project firmly in bulk-delivery territory, so a single delivered load plus the separate base material is a more practical plan than counting bags.
Gravel surface for a 40 ft garden walkway
A 3 ft wide walkway running 40 ft to a gate is finished with a 3 in gravel surface. The same delivery has to cover this section as well as the pad above.
Inputs
- Material
- Gravel (crushed stone)
- Area
- 3 ft × 40 ft
- Depth
- 3 in
- Waste
- 10%
Results
- Project area
- 120 sq ft11.15 m²
- Depth used
- 3 in
- Volume before waste
- 30 cu ft1.11 cu yd
- Waste allowance
- 10%
- Volume to order
- 33 cu ft1.22 cu yd · 0.93 m³
- Order quantity
- 1.25 cu ydRounded up to the nearest 0.25 cu yd
- Estimated weight
- 1.71 tons1.55 tonnes at the 1.4 tons/cu yd planning density
- 0.5 cu ft bags
- 66 bags
- Bags or bulk?
- Bags or bulk delivery are both reasonable
Small projects are where bagged material starts to compete with bulk delivery, and the bag rows show why: the walkway alone would need far more bags than most people want to carry. Adding the area into the same calculator session as the pad gives one combined order instead of two trips.
How much waste allowance do you actually need
Waste is not a guess about quality; it covers the gravel that ends up somewhere other than the finished surface. Where the ground is uneven, where material is moved by wheelbarrow instead of a chute, and where the layer is raked to a grade, that allowance earns its place.
- A flat, machine-spread surface over a prepared subgrade needs the least: often nothing beyond the order rounding.
- Hand-placed walks and patios with edging, curves or tight corners sit in the middle, where 10% is a sensible planning figure.
- A long carry from the delivery point, or a slope the material will creep down, justifies more.
- Anything above 25% should have a specific reason. The calculator warns above that threshold because an unexplained allowance usually means the measurement is wrong rather than the site being that difficult.
Bags or bulk delivery
Gravel comes in 0.5 cu ft bags, in bulk by the cubic yard, or by the ton. The calculator converts your volume into all of those units at once and suggests which is likely to be practical, based only on volume.
| If you order | What the calculator shows | Watch out for |
|---|---|---|
| By the cubic yard | The volume after compaction and waste, rounded up to the nearest 0.25 cu yd | Delivery minimums, and how far the truck can get from the work area |
| By the ton | Cubic yards multiplied by the supplier density you enter | The same volume weighs less dry and more when saturated |
| By the bag | Total cubic feet divided by the fill volume printed on the product | Bag fill volumes vary by brand; 0.5 cu ft is the common size for bagged stone |
The calculator never supplies a price. Cost rows only appear after you enter your own supplier price.
As a planning cue rather than a rule: below roughly half a cubic yard, bags are convenient. Between half a cubic yard and two cubic yards it can go either way. Above two cubic yards, bulk delivery is usually easier, provided a truck can reach the work area.
Common mistakes and how they show up
| Mistake | What it does to the order | Fix |
|---|---|---|
| Measuring the finished surface instead of the subgrade | Overstates the area, because a graded surface spreads wider than the layer beneath it | Run the tape at the level the gravel will sit on |
| Mixing up cubic yards and tons | A quote can look far cheaper than it is, because the units are different | Ask which unit the price is quoted in, then compare like for like |
| Using one depth everywhere | Oversupplies quiet areas and undersupplies the ones taking traffic | Give each use its own area and depth |
| Ignoring compaction on a compactable layer | The finished layer comes up short after it is worked | Turn on the compaction allowance for anything being compacted |
| Forgetting fabric, edging or the base | The stone arrives and the preparation is not done | Buy and stage the other components before the delivery date |
What to have ready when you call the supplier
Supplier checklist
- The area, the depth, and the finished order quantity in cubic yards
- The stone size and type, described using the supplier catalogue name
- Whether you want the price by volume or by weight
- The delivery address, plus where the truck can safely place the load
- Whether the load must be placed rather than tipped, and whether the access is wide enough
- The delivery date, and how wide the arrival window can be
- Whether the supplier can split the load between two stone types for a base and a surface
If the delivery is going to sit on the driveway until the weekend, say so. Damp bulk stone left in a pile for a week is heavier and harder to move than fresh material, and it will stain some surfaces.
Where this fits with the rest of the plan
Go deeper
- Gravel: size, uses and what to ask forHow crushed stone differs by gradation, and what that means for a walkway or a base
- What actually changes the price of gravelMaterial type, quantity, delivery and site access
- How to plan a gravel drivewayMulti-layer planning for a surface that takes vehicles
- Landscaping material planning workflowOne measurement process for gravel, soil, sand and pavers
Try it: Gravel Calculator
Calculate gravel volume, tons, bags, waste and cost. Every number on this page came from the same engine, so you can replace the example figures with your own measurements and compare.
- Gravel CalculatorCalculate gravel volume, tons, bags, waste and cost.
- Driveway Gravel CalculatorEstimate layered driveway base, middle and surface materials.
- Pea Gravel CalculatorEstimate pea gravel for paths, gardens and patios.
- Paver Base CalculatorEstimate compactable base material for patios and walkways.
Frequently asked questions
Should I order gravel by the cubic yard or by the ton?
Order in the unit your supplier quotes in, and use the calculator to convert between them. Cubic yards describe the space the material fills, which is what your project actually consumes. Tons describe the weight on the truck, which is how many suppliers prefer to invoice. Compare quotes only after converting both to the same unit.
How many square feet does one cubic yard of gravel cover?
It depends entirely on depth, which is why covering area alone is a misleading way to shop. One cubic yard is 27 cubic feet, so at 3 in deep it covers about 108 sq ft, and at 1 in deep it covers about 324 sq ft. Enter a volume and a depth in the calculator to see the coverage figure for your own numbers.
Is 2 inches deep enough for gravel?
Two inches is inside the planning range the calculator uses for walkways and patios, and it is a common depth for a decorative surface over a firm, prepared base. It is not enough on soft or poorly drained ground, and it is not what you would plan for a surface taking vehicle traffic. The calculator flags depths outside the typical range but leaves the decision to you.
Why does the calculator show both tons and tonnes?
A US short ton is 2,000 lb and a metric tonne is about 2,205 lb, so the numbers differ by roughly 10%. Showing both avoids the common confusion when a supplier or a product data sheet uses the other unit.
Does the calculator include the price of gravel?
No. It never invents a price. Cost output appears only after you type in a price from your own supplier quote, and it then multiplies that price by the calculated quantity so you can compare a per-yard quote with a per-ton quote.
Method and limitations
Where this estimate stops being useful
The calculator models a volume of material. It does not know how well drained your ground is, how deep the frost goes, what is under the surface, or how much load the finished surface has to carry. Gravel density varies by rock type, gradation and moisture, so a tonnage estimate can move by a meaningful amount even when the volume is right. Treat the output as the quantity to start a conversation with, not as a specification or an engineering conclusion.
The methodology page documents how volume, waste, compaction and purchase quantities are produced, and the about page explains what this platform does and does not do.