Gravel Calculator

This gravel calculator helps you estimate how much gravel you need for a project—then converts that volume into practical weight units like tons and kilograms. Use it for driveways, patios, drainage trenches, base layers, and more when you want a fast but informed estimate before ordering.

Choose a measurement mode (rectangular, circular, or direct volume), pick your units, and adjust density plus a waste/compaction factor. For more tools in the same vein, explore Engineering Calculators or browse All Calculators.

If your work is more measurement-heavy, you may also find Scientific Calculators useful when comparing unit conversions and ratios.

Calculator Tool

All calculations run locally in your browser.

Length

Enter the project length in your selected unit.

Width

Width uses the same unit as Length for cleaner entry.

Depth

Depth is often entered in inches/cm for gravel base layers.

Circular mode tip

Switch to “Circular Area” if you’re filling a round pad, firepit zone, or tree ring.

Gravel density preset

Density varies by supplier, moisture, and gradation.

Density value

Helper: density varies; defaults are estimates.

Add extra % (waste/compaction)

Adds a buffer for settling, compaction, and minor measurement error.

Price per unit (optional)

No currency conversion—enter your local rate.

Pickup load assumption

Used only for a delivery note estimate (edit if needed).

Keyboard & screen reader ready

All fields have labels, focus styles, and results updates announce politely.

Results

Volumes and weights include your “extra %” buffer.

Calculating…

Volume

Cubic yards (yd³)

0yd³

Cubic feet (ft³)

0ft³

Cubic meters (m³)

0m³

Project size

Gauge shows a simple “project size” bucket based on total yd³ (small → large).

yd³ vs 10 yd³ reference

0.00 yd³

m³ vs 7.65 m³ reference

0.00 m³

Weight & Delivery

US short tons

0tons

Metric tonnes

Pounds

0lb

Kilograms

0kg

Delivery note will appear after calculation.

Estimated material cost

$—

Results Summary will appear here after you calculate.

Show calculation steps

Below is a step-by-step breakdown using your selected mode (rectangular, circular, or direct volume), including unit conversions, density conversion (if needed), and the extra % factor.

Calculate to see the substituted formula and conversions.

How It Works (Formulas + Variables)

The calculator estimates volume first, then converts volume into weight using your chosen gravel density. Finally, it applies your extra % (waste/compaction buffer) consistently to volume, weight, and cost.

Variables (common): L = length, W = width, D = depth, r = radius, V = volume. Density is entered as lb/ft³ or kg/m³ and converted internally.


Rectangular Area:
  V = L × W × D

Circular Area:
  V = π × r² × D
  (If diameter is given: r = diameter ÷ 2)

Extra % (waste/compaction):
  V_final = V_base × (1 + extra%/100)

Weight (using lb/ft³ base):
  Weight_lb = V_ft3 × Density_lbft3
  US short tons = Weight_lb ÷ 2000
  kg = Weight_lb × 0.45359237
  metric tonnes = kg ÷ 1000

Volume conversions:
  1 yd³ = 27 ft³
  1 m³ = 35.3146667215 ft³
  1 yd³ = 0.764554857984 m³
Density conversion:
  1 lb/ft³ = 16.0184634 kg/m³

After you calculate, the Results section also shows the exact formula used with your substituted values and the conversion path (for example, inches → feet, ft³ → yd³, and any density conversion).

Use Cases (Real Projects)

Driveway base layer

Estimate base gravel for a driveway where depth is often 4–8 inches depending on soil and traffic. Consider compaction and order extra if you’re blending multiple stone sizes or working over soft subgrade.

Patio or paver sub-base

For patios, a compacted gravel base is commonly 3–6 inches. Measure the footprint carefully and keep depth consistent—small depth errors can change tonnage quickly over a large area.

Drainage trench / French drain

Trenches often have uneven sides and depth changes. Use the rectangular mode with average dimensions, then add extra % to cover voids, settling, and shape irregularity—especially around pipe bedding.

Garden path and walkways

Paths frequently use 2–4 inches of decorative gravel. Wet or fine gravel can pack differently, so factor compaction and consider edging to reduce “spread” over time.

Shed or small slab foundation base

A level base under a shed helps prevent settling and improves drainage. Measure length/width precisely and use a realistic density—crushed stone often weighs more per cubic foot than pea gravel.

Worked Examples (With Numbers)

Example 1: Driveway base (rectangular)

Given: L = 30 ft, W = 10 ft, D = 4 in, Density = 105 lb/ft³, Extra = 10%

D in feet = 4 ÷ 12 = 0.3333 ft

Base volume V = 30 × 10 × 0.3333 = 100.0 ft³

Final volume = 100.0 × 1.10 = 110.0 ft³ = 110.0 ÷ 27 = 4.07 yd³

Weight = 110.0 × 105 = 11,550 lb = 11,550 ÷ 2000 = 5.78 US tons

Example 2: Round firepit zone (circular)

Given: Diameter = 8 ft, Depth = 3 in, Density = 95 lb/ft³, Extra = 10%

Radius r = 8 ÷ 2 = 4 ft

Depth D = 3 ÷ 12 = 0.25 ft

Base volume V = π × 4² × 0.25 = π × 16 × 0.25 = 12.57 ft³

Final volume = 12.57 × 1.10 = 13.82 ft³ = 13.82 ÷ 27 = 0.51 yd³

Weight = 13.82 × 95 = 1,313 lb ≈ 0.66 US tons

Example 3: Known volume from plans (volume direct)

Given: V = 2.0 yd³, Density = 100 lb/ft³, Extra = 10%

Convert to ft³: 2.0 × 27 = 54.0 ft³

Final volume = 54.0 × 1.10 = 59.4 ft³ = 2.20 yd³

Weight = 59.4 × 100 = 5,940 lb = 2.97 US tons

Also: kg = 5,940 × 0.45359237 = 2,694 kg ≈ 2.69 tonnes

Common Mistakes

Mixing units (feet for length but inches for width) without converting everything to a consistent base.
Using “loose” depth measurements when the gravel will be compacted (final depth changes volume).
Skipping the extra % buffer, then coming up short after settling, grading, and minor spill.
Picking an unrealistic density for the gravel type (pea gravel often differs from crushed stone).
Ignoring wet conditions—water in voids can increase delivered weight even when volume is the same.

Quick Tips

Measure length and width at multiple points, then use an average if the edges aren’t perfectly straight.
Plan depth by function: decorative paths often 2–4 in, base layers can be 4–8 in depending on load.
Order slightly extra (often 5–15%) to cover compaction, grading, and small shape irregularities.
Confirm how your supplier sells material: by ton, by yard, or by bag—and match your estimate to that unit.
If rain is expected, consider that wet gravel can weigh more per load even if the cubic volume is unchanged.

FAQ

Accuracy depends on measurements, real depth after compaction, and the supplier’s actual density. The calculator is designed for planning and ordering, so it’s best to treat results as an estimate rather than an exact invoice weight. Use average dimensions for irregular edges, and apply an extra % buffer if you expect settling or you’re shaping grades. If your supplier provides a specific weight per yard or per tonne for your gravel, use that density for the closest match.

Typical depth depends on use and subgrade. Decorative garden paths often use about 2–4 inches. Many patios or paver sub-bases are commonly around 3–6 inches when compacted. Driveway base layers are often 4–8 inches, especially where soil is soft or traffic is heavier. Measure the intended finished thickness, not the loose pile depth. If you compact the base, consider adding extra % so your delivered quantity covers settling and grading.

Density changes with stone type, gradation, and void space. Crushed stone can pack tighter and may weigh more per cubic foot than rounded pea gravel. Limestone, granite, and mixed aggregate can also differ based on mineral composition. Moisture affects density too because water fills voids and increases weight without changing the solid rock amount. That’s why supplier specs can vary by region and product. If your supplier lists weight per yard or per tonne for a specific material, use that number for the best estimate.

Wet gravel contains extra water trapped between stones and in fine particles. The volume you spread may look the same, but the load weight increases because water adds mass. This matters if you’re buying by the ton or comparing truckload capacity. It also affects compaction because damp material can settle differently than very dry material. If you’re ordering near rain or from stockpiles stored outdoors, add a small buffer and consider confirming expected weight ranges with the supplier to avoid surprises at delivery.

A US short ton equals 2,000 pounds. A metric tonne (often written as “tonne” or “t”) equals 1,000 kilograms, which is about 2,204.62 pounds. Because they’re different sizes, a supplier quote in tonnes will not match a quote in US tons for the same weight in pounds. This calculator shows both systems plus pounds and kilograms so you can compare easily. When ordering, confirm which ton unit your supplier uses, especially if you’re mixing US and metric references.

For irregular areas, break the space into simpler shapes you can measure—rectangles, circles, or strips—and calculate each part, then add them together. For slopes, use an average depth: measure thickness at several points and take the mean, or estimate based on the design grade. Because uneven areas create extra voids and edge loss, it’s smart to increase the extra % buffer. If precision matters, consider measuring with string lines and stakes, or use a plan-based volume and enter it directly in the Volume Direct mode.

Many projects benefit from ordering extra to cover compaction, grading, and minor measurement error. A common planning range is about 5–15%, but it depends on how consistent your depth is and how “messy” the edges are. For trenches, slopes, or areas with soft subgrade, higher extra % can prevent shortages. The calculator’s extra % field applies the buffer to both volume and weight so the results reflect what you’re likely to order. If you can return unused material, a little extra is usually safer than running short.

Truckload estimates depend on the truck type and how the supplier loads it. A simple planning method is to divide your required cubic yards by an assumed capacity. This page includes a pickup-load assumption (default 0.5 yd³) so you can get a quick “how many trips” estimate for small jobs. For larger deliveries, suppliers may quote by dump truck capacity or by tonnage limits, which can vary with wet material. Use the note as a rough guide, then confirm delivery sizes with your local supplier to match their equipment.

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Accuracy & Notes

Runs locally in your browser: inputs stay on your device (no data sent anywhere). Rounding policy: volumes show 2 decimals, tons/tonnes show 2 decimals, truckloads show 1 decimal. Minor rounding differences are normal.

Last Updated: January 20, 2026

Sources & References: supplier specifications for aggregate density, and common construction estimating practice (density ranges vary by region, gradation, and moisture).

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