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Aggregate Calculator: Estimate Gravel, Sand, or Crushed Stone

An aggregate calculator helps you estimate how much sand, gravel, crushed stone, or limestone you need for a project like a driveway, walkway base, patio sub-base, shed pad, or drainage trench.

This specific calculator is built around the same workflow most contractors and material suppliers use:

1. Measure the project footprint (length and width).
2. Choose a compacted layer thickness (depth).
3. Compute volume (cubic feet → cubic yards).
4. Convert volume to tons using an estimated material density (tons per cubic yard).
5. Add a compaction/waste allowance (typically 5%–10% for base materials, depending on conditions).
6. Round up to a practical order size so you don’t come up short.

This Aggregate Calculator Online is designed to answer those questions quickly, with transparent math.

How the calculator works (the exact logic)

1) Units: Imperial or Metric

The tool lets users switch between:

• Imperial: Length (ft), Width (ft), Depth (in)
• Metric: Length (m), Width (m), Depth (cm)

Behind the scenes, everything is converted to cubic feet, then to cubic yards, then to tons.

2) Volume formula

The core formula is the standard construction volume equation:

Volume = Length × Width × Depth

For imperial inputs, depth is entered in inches and converted to feet:

• Depth (ft) = Depth (in) ÷ 12

Then:

• Volume (ft³) = L(ft) × W(ft) × Depth(ft)

For metric inputs, the calculator first computes cubic meters:

• Volume (m³) = L(m) × W(m) × Depth(m)
• where Depth(m) = Depth(cm) ÷ 100

Then it converts cubic meters to cubic feet using:

• 1 m³ = 35.3147 ft³ (conversion factor)
  Source: NIST unit conversion references for SI/US customary usage. https://www.nist.gov/pml/owm/metric-si/si-units

3) Convert cubic feet to cubic yards

Material is commonly ordered in cubic yards (yd³) in the US.

• Volume (yd³) = Volume (ft³) ÷ 27
  Because 1 yard = 3 feet, so 1 cubic yard = 3 × 3 × 3 = 27 cubic feet (direct geometric conversion).

4) Convert cubic yards to tons (by density)

The calculator uses tons per cubic yard (tons/yd³) to estimate weight:

• Tons = Volume (yd³) × Density (tons/yd³)

It provides common “rule-of-thumb” densities in the dropdown:

• Crushed stone (avg 1.5 tons/yd³)
• Gravel (avg 1.4 tons/yd³)
• Sand (avg 1.35 tons/yd³)
• 2″ crushed limestone (~1.6 tons/yd³)
• Or Custom density

Important: density changes with moisture, gradation, compaction, and void space. Treat these as planning averages and confirm with your supplier’s spec sheet (many suppliers will tell you their material’s tons-per-yard conversion).

5) Add compaction / waste allowance

The tool lets you enter a percent “extra” (0–30%). It calculates:

• Adjusted volume = Base volume × (1 + compaction%)
• Adjusted tons = Base tons × (1 + compaction%)

This is practical because:

• base layers often “lose” volume when compacted,
• subgrade can be uneven,
• material can spill or migrate during grading.

6) Headline recommendation rounding

The calculator also provides a “recommended order size” by rounding up:

• cubic yards: up to nearest 0.5 yd³
• tons: up to nearest 0.25 ton

That rounding is conservative on purpose: running short is usually more expensive than having a little extra.

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Example 1: Driveway base (imperial) — 20 ft × 12 ft × 3 in

This is a very common long-tail search: “how much gravel for a driveway 20×12 at 3 inches”.

Inputs

• Length = 20 ft
• Width = 12 ft
• Depth = 3 in
• Material = crushed stone (1.5 tons/yd³)
• Compaction/waste = 10%

Step 1: Convert depth to feet

• 3 in ÷ 12 = 0.25 ft

Step 2: Volume in cubic feet

• Area = 20 × 12 = 240 ft²
• Volume = 240 × 0.25 = 60 ft³

Step 3: Convert to cubic yards

• 60 ÷ 27 = 2.222222… yd³

Step 4: Convert to tons

• 2.222222… × 1.5 = 3.333333… tons

Step 5: Add 10%

• Adjusted yd³ = 2.222222… × 1.10 = 2.444444… yd³
• Adjusted tons = 3.333333… × 1.10 = 3.666666… tons

Step 6: Round up (tool’s headline)

• Yards: 2.4444… → round up to nearest 0.5 → 2.5 yd³
• Tons: 3.6666… → round up to nearest 0.25 → 3.75 tons

So you’d see a headline close to:
2.50 yd³ (~3.75 tons)

Example 2: Metric project — 6.1 m × 3.7 m × 7.5 cm

This matches searches like “metric gravel calculator meters to tons”.

Inputs

• Length = 6.1 m
• Width = 3.7 m
• Depth = 7.5 cm (which is 0.075 m)

Step 1: Volume in cubic meters

• Area = 6.1 × 3.7 = 22.57 m²
• Volume = 22.57 × 0.075 = 1.69275 m³

Step 2: Convert to cubic feet

• 1.69275 × 35.3147 = 59.778958425 ft³ (≈ 59.78 ft³)
  Source for m³→ft³ factor: NIST. 

Step 3: Convert to cubic yards

• 59.778958425 ÷ 27 = 2.214036… yd³ (≈ 2.21 yd³)

From there, the calculator continues exactly like the imperial workflow.

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Tips to get a more accurate Aggregate Calculator estimate

Measure thickness the way the material will be installed

Decide whether your “depth” means:

• Loose depth (before compaction), or
• Compacted depth (what you want after plate compactor/roller)

Most people want a compacted thickness, then add extra using the compaction/waste %.

Break irregular shapes into rectangles

If your area isn’t a perfect rectangle:

• split it into 2–6 rectangles,
• calculate each one,
• add the volumes.

This is one of the best ways to reduce over/under-ordering without needing advanced geometry.

Run separate calculations for layered builds

Common long-tail need: “gravel base + sand leveling layer calculator”.

If you’re doing layers (example):

• 4″ base stone
• 1″ leveling sand
• pavers on top

Run the calculator once per layer with the correct depth and (if needed) different density.

Use “custom density” if your supplier gives a conversion

Suppliers often sell by the ton but may quote:

• “X tons covers Y square feet at Z inches,” or
• a specific tons-per-yard factor for their product.

If you have that number, entering a custom density is the fastest way to align the calculator with real-world ordering.

Always round up—especially for base layers

Base stone and gravel rarely spread perfectly:

• subgrade isn’t flat,
• edges feather out,
• material settles into soft spots.

Rounding up prevents a second delivery (which often costs more than extra material).

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FAQs/ Frequently Asked Questions

This Aggregate Calculator is built for real ordering decisions: it turns length, width, and depth into cubic feet, cubic yards, and estimated tons, then lets you add a realistic compaction/waste allowance and rounds up to a practical purchase amount.

You can explore Similar Calculator like this Free sobriety calculator.