Gravel Calculator

Project use:

Choose the job type closest to the area being filled.

Footprint mode:

Use rectangle, circle, or a known total area.

Length:

Enter the measured run of the area to fill.

Width:

Enter the average width using the same unit family.

Diameter:

Enter the full circular footprint diameter.

Total coverage area:

Enter the surface area that will receive gravel.

Finished depth:

Enter the installed gravel layer depth.

Depth slider {{ depthRangeValueLabel }}

Gravel type:

Pick the closest aggregate, then adjust density if your supplier gives one.

Density:

Enter supplier density as kg/m3, tonne/m3, or short tons per cubic yard.

Waste and compaction allowance:

Use 0 for exact volume or add a practical ordering allowance.

Allowance slider {{ formatNumber(wastePercentValue, 0) }}%

Supplier order unit:

Choose cubic metres, metric tonnes, cubic yards, or short tons to match the supplier quote.

Matching zones:

Keep at 1 for a single measured area.

zones

Order increment:

Use 0.5 or 1 when the supplier sells in half-ton or whole-yard increments.

Delivery minimum:

Leave at 0 when no minimum applies.

Price per metric tonne:

Enter 0 to omit metric-tonne cost estimates.

$ / tonne

Price per cubic metre:

Enter 0 to omit cubic-metre cost estimates.

$ / m3

Price per ton:

Enter 0 to omit ton-based cost estimates.

$ / ton

Price per cubic yard:

Enter 0 to omit cubic-yard cost estimates.

$ / cu yd

Bag weight:

Enter bag weight in kg or pounds, or 0 to skip bag counts.

Measure	Value	Detail	Copy
{{ row.measure }}	{{ row.value }}	{{ row.detail }}

Scenario	Depth	Volume	Weight	Buying note	Copy
{{ row.scenario }}	{{ row.depth }}	{{ row.cubicYards }}	{{ row.tons }}	{{ row.note }}

Check	Status	Detail	Copy
{{ row.check }}	{{ row.status }}	{{ row.detail }}

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Bulk gravel jobs turn a surface measurement into a purchase decision. The space on the ground may be a rectangle, circle, trench, path, or irregular bed, but the material is ordered as a volume or a weight. That shift is where mistakes happen: a few inches of depth spread across a wide footprint can add another cubic yard, and the same pile may be quoted by cubic metre, cubic yard, short ton, metric tonne, or retail bag.

Depth, density, and allowance do different jobs. Finished depth describes the installed thickness. Bulk density converts that volume into estimated weight. Allowance covers compaction, edge loss, uneven grade, and small measuring errors before supplier rounding raises the estimate to a selling increment or delivery minimum. Keeping those ideas separate makes a quote easier to check.

Common gravel planning situations and estimating cautions
Situation	Quantity question	Main caution
Decorative bed	How much stone covers the visible surface?	Too much depth can bury edging, plants, or fabric.
Garden path	How much material gives a walkable finished depth?	Curves and tapered widths should be averaged or split into smaller areas.
Driveway surface	How many yards or tons cover the top layer?	The estimate does not prove the base is strong enough for traffic.
Driveway base	How much compactable aggregate fills the planned thickness?	Subgrade, drainage, gradation, and compaction control performance.
Drainage bed	How much open stone fills a trench, pit, or bed?	Void space, geotextile, pipe volume, and local drainage design can change the specification.

Gravel quantity path from footprint and depth to density and supplier order

Material names are useful shortcuts, not exact engineering values. Crushed stone usually packs and drains differently from rounded river rock. Pea gravel may be easy to spread but less stable under traffic. Limestone base and other dense-graded aggregates can carry load only when the underlying soil, moisture, fines content, and compaction are handled correctly.

A quantity estimate cannot approve a driveway base, drainage system, slope, or load-bearing surface. Those jobs can depend on subgrade strength, aggregate gradation, geotextile, frost exposure, compaction equipment, and local specifications. Use the calculated quantity to plan the order and compare supplier quotes, then confirm the construction detail when performance matters.

How to Use This Tool:

Measure the footprint first, then choose the material and supplier assumptions that turn that footprint into an order quantity.

Choose Project use to load a starting depth, allowance, gravel type, and depth review band. Pick Custom gravel plan when a drawing, contractor note, or supplier sheet already sets those values.
Set Footprint mode to Rectangle, Circle, or Known area. The gravel-bed sketch should match the footprint you measured before the summary is trusted.
Enter length and width, diameter, or total coverage area with the matching units. Open Advanced and set Matching zones when repeated beds, stalls, pads, or path sections share the same footprint and depth.
Enter Finished depth and review the depth badge. A low or high badge means the depth falls outside the selected project-use planning band, not that the arithmetic failed.
A shallow driveway-base entry can still produce an order size. Treat the warning as a specification check before buying material.
Pick Gravel type, then replace Density with a supplier value when available. Density can be entered as kg/m3, tonne/m3, or ton/cu yd.
Set Waste and compaction allowance, Supplier order unit, and any Advanced Order increment or Delivery minimum. Add prices or Bag weight only when cost or bag-count checks matter.
Review Order Estimate first, then use Depth Scenarios, Density Ledger, and Tonnage Curve to check sensitivity. If the summary says Measurements needed, correct the positive area, depth, or density value named in the warning.

Interpreting Results:

Recommended order is the supplier-facing number because it includes allowance, delivery minimums, and selling increments. Base volume shows the measured fill before margin, so it is the better value for checking whether the area and depth were entered correctly. Estimated weight depends on density and should be treated as a planning number unless it uses the supplier's own bulk-density value.

The depth badge is a warning cue, not a construction approval. Depth in band means the entered finished depth sits inside the planning range for the selected project use. It does not prove that a driveway base is compacted, a drainage bed has enough void space, or a slope will stay stable. Confirm aggregate type, gradation, subgrade preparation, and construction details before relying on the material quantity for performance.

How to read gravel calculator result fields
Result field	Use it for	Verify before ordering
Coverage area	Checking the measured footprint and repeated zones.	Confirm units and average irregular edges.
Order volume	Comparing cubic metre and cubic yard quantities after allowance.	Confirm the supplier sells by volume, not by scale weight.
Estimated weight	Comparing metric tonnes and short tons from the selected density.	Use supplier density for tight orders or unusual aggregate.
Supplier cross-check	Translating a rounded order into the other common quote units.	Make sure the quote unit matches the selected order unit.
Haul weight	Spotting orders that are heavy enough to need delivery planning.	Do not use it as a vehicle payload or trailer-rating approval.

Use the Tonnage Curve to see how depth changes order size. If a small depth change moves the job into a new delivery increment, check the rounded order against the finished depth you actually want instead of buying extra material only because the supplier step changed.

Technical Details:

Gravel quantity starts with geometry and then moves into material behavior. Rectangle, circle, and known-area footprints give a calculated area; finished depth turns that area into volume. Weight is less certain because loose aggregate density changes with particle size distribution, particle shape, void space, moisture, and compaction state.

Allowance is added before supplier rounding. That order matters because the selling increment or delivery minimum should apply to the practical buying quantity, not the bare geometric volume. A half-ton increment, for example, rounds after allowance-adjusted tonnage has been calculated.

Formula Core:

The primary volume path is area times finished depth, followed by allowance and density conversion.

\begin{array}{lcl} A_{rect} & = & L \times W \\ A_{circle} & = & π \times {(\frac{d}{2})}^{2} \\ V_{base} & = & A \times D \\ V_{order} & = & V_{base} \times (1 + \frac{P}{100}) \\ T & = & \frac{V_{order}}{27} \times ρ \end{array}

Here, A is footprint area in square feet, L and W are rectangle dimensions in feet, d is circle diameter in feet, D is finished depth in feet, P is allowance percent, ρ is density in short tons per cubic yard, and T is estimated short tons. One cubic yard is 27 cubic feet, one cubic foot is 0.028316846592 cubic metre, one short ton is 2,000 pounds, and one metric tonne is 1,000 kg.

A 30 ft by 10 ft driveway surface at 3 in depth covers 300 sq ft. Base volume is 75 cu ft, or 2.78 cu yd. With a 10% allowance, order volume is 82.5 cu ft, or 3.06 cu yd. At 1.50 ton/cu yd, estimated weight is 4.58 short tons, which is 4.16 metric tonnes before any supplier increment or delivery minimum is applied.

Project Assumptions:

Project assumptions used for gravel depth and allowance presets
Project use	Default depth	Allowance	Default material	Depth review band
Driveway top layer	3 in	10%	Crushed stone	2 to 4 in
Driveway base	5 in	12%	Limestone base	4 to 8 in
Walkway or garden path	3 in	8%	Pea gravel	2 to 4 in
Drainage bed	6 in	10%	River rock	4 to 12 in
Decorative landscape bed	2 in	6%	Pea gravel	1.5 to 3 in
Custom gravel plan	3 in	0%	Custom density	No preset band

Density and Rounding:

Density presets and order rounding rules used by the gravel calculator
Item	Rule or value	Why it matters
Crushed stone	1.50 ton/cu yd	Default for driveway top-layer estimates.
Pea gravel	1.35 ton/cu yd	Default for paths and decorative beds.
River rock	1.45 ton/cu yd	Default for drainage-bed estimates.
Decomposed granite	1.35 ton/cu yd	Useful for fine aggregate planning.
Limestone base	1.55 ton/cu yd	Default for driveway base estimates.
Custom density	0.10 to 4.00 ton/cu yd after conversion	Use when the supplier gives kg/m3, tonne/m3, or ton/cu yd.
Delivery minimum	Raises the order to at least the entered minimum	Matches yards or quarries with a minimum delivered quantity.
Order increment	Rounds upward to the next entered selling step	Prevents underbuying when material is sold in half-ton, whole-yard, or similar steps.

Cost checks multiply the rounded recommendation by any entered unit price for metric tonnes, cubic metres, short tons, or cubic yards. Bag count divides the rounded metric-tonne equivalent by the entered retail bag weight and rounds up to whole bags.

Accuracy Notes:

The arithmetic is deterministic, but field conditions are not. Aggregate can be delivered wet, stockpile density can differ from dry test values, and compacted thickness can vary across soft spots or uneven base preparation. Edge loss and grading corrections are practical allowances, not exact material properties.

For irregular spaces, split the job into simpler rectangles, circles, or known-area sections before adding totals. For structural driveway work, drainage systems, heavy vehicle loads, retaining edges, steep slopes, or code-driven work, use the estimate only as a quantity aid and confirm material type, depth, and compaction requirements with a qualified source.

Advanced Tips:

Use Matching zones for repeated pads, stalls, tree rings, or path sections only when each zone has the same footprint and finished depth.
Set Supplier order unit to match the quote before entering Order increment or Delivery minimum; rounding happens in that selected unit.
Replace preset density with the supplier's kg/m3, tonne/m3, or ton/cu yd value when the job is tight, the aggregate is unusual, or the material may be wet.
Compare the Depth Scenarios before ordering when the depth badge is low or high; a one-inch correction can change tonnage across a large footprint.
Use cost checks as material-only comparisons. Delivery fees, taxes, equipment, geotextile, edging, base preparation, and disposal are outside the calculation.

Worked Examples:

Metric driveway surface

A 9 m by 3 m rectangle at 8 cm finished depth covers 290.6 sq ft. With crushed stone at 1.50 ton/cu yd and a 10% allowance, Order volume is 2.376 m3, or 3.11 cu yd. Recommended order is 4.23 metric tonnes when no delivery minimum or increment is entered.

Drainage bed rounded by short tons

A 12 ft diameter circular drainage bed at 6 in depth covers about 113.1 sq ft. River rock with a 10% allowance produces 2.30 cu yd and 3.34 short tons. If Supplier order unit is short tons and Order increment is 0.5, Recommended order rounds up to 3.50 short tons.

Driveway base depth warning

A 40 ft by 12 ft driveway base entered at 3 in depth still produces a quantity estimate: about 4.98 cu yd and 7.72 short tons after the 12% allowance. The Depth band should read low for driveway base because the preset review band is 4 to 8 in, so the specification should be checked before ordering.

Missing footprint value

If rectangle mode has a positive length but the width is zero, the page reports Enter a positive footprint area and the result tables should not be used. Add the missing width, switch to circle mode, or enter a measured known area before comparing supplier quantities.

FAQ:

Why do cubic yards and tons both appear?

Cubic yards and cubic metres describe volume. Short tons and metric tonnes estimate weight from the selected density. Suppliers quote both ways, so the result includes cross-checks for volume and weight.

Should I trust the preset density?

Use the preset for early planning, then replace it with supplier density when the order is tight. Material source, gradation, moisture, and compaction can move the weight per cubic yard.

What does the allowance percentage do?

Allowance increases the base volume before order units, cost checks, bag count, and depth scenarios are calculated. A 10% allowance turns 3.00 cu yd of measured need into 3.30 cu yd before supplier rounding.

Why does the page say measurements are needed?

The result needs a positive footprint area, a positive gravel depth, and a positive density. Check the active footprint mode first because a missing width, diameter, or known-area value can make the area zero.

Can the result confirm that a driveway base is strong enough?

No. The result estimates quantity only. Driveway base performance depends on subgrade, drainage, aggregate gradation, compaction, layer thickness, traffic, and local construction requirements.

Are my measurements sent to a server?

The calculation runs in the browser. If you copy or share the page URL after changing values, those values may be included in the URL, so avoid sharing a link when project dimensions or prices are private.

Glossary:

Cubic yard: A volume of 27 cubic feet, commonly used for bulk landscape and construction aggregate.
Finished depth: The intended installed gravel thickness after spreading and site preparation.
Short ton: A U.S. weight unit equal to 2,000 pounds.
Density: The weight per unit volume used to convert gravel volume into estimated tonnage.
Allowance: An added percentage for compaction, grading variation, edge loss, and ordering margin.
Order increment: The supplier selling step used to round the recommended order upward.
Delivery minimum: The smallest quantity a supplier will deliver or bill for in the selected order unit.

References:

C29/C29M Standard Test Method for Bulk Density ("Unit Weight") and Voids in Aggregate, ASTM International, October 6, 2023.
User Guidelines for Waste and Byproduct Materials in Pavement Construction: Granular Base Application Description, Federal Highway Administration.
Geotechnical Aspects of Pavements Reference Manual, Chapter 7.3 Base Layers, Federal Highway Administration.
Natural Aggregates Statistics and Information, U.S. Geological Survey.