CalcaTools

Fill Dirt Calculator | Estimate fill dirt volume for a job

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Estimate how much fill dirt you need in cubic yards and tons for any excavation or grading project. Enter the length, width and depth, and the tool converts the volume to weight using standard soil density — essential for ordering and budgeting earthwork.

Last updated: July 2026 · Free · No sign-up required

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Results

Enter values above and click Calculate to see your result instantly.

Quick reference

Coverage depthArea per cubic yard
1 inch324 sq ft
2 inches162 sq ft
3 inches108 sq ft
4 inches81 sq ft
6 inches54 sq ft

info Fill Dirt Calculator

Free math calculator — enter your numbers and get an instant, accurate result.

info Private by design

Everything runs locally in your browser. No uploads, no accounts, no tracking.

info Works everywhere

Fully responsive and mobile-friendly — calculate on any device, any time.

info Educational

Includes the formula and step-by-step explanation so you understand the math, not just the answer.

Interpretation guide

ResultWhat it tells you
Cubic yardsVolume to order — bulk compacted fill dirt is sold by the cubic yard.
Estimated tonsWeight for by-the-ton pricing (≈ 1.35 tons per cubic yard).
Add 5–10%%Order a little extra for compaction, spillage and uneven ground.

lightbulb Worked example

Let's say you are using the Fill Dirt Calculator. Fill Dirt Calculator is a free online calculator that helps you work out fill dirt quickly and accurately, right in your browser. Enter the values that match your situation into the input fields and press calculate — using realistic numbers makes the result directly useful for you.

Result: The calculator instantly applies the formula Cubic yards = (Length_ft × Width_ft × Depth_in ÷ 12) ÷ 27; Tons = cubic yards × 1.35 and returns the result with appropriate precision.

What this means: Read the result in the context of what you are measuring. The step-by-step breakdown lets you confirm the math and understand which input most affects the outcome.

Formula & methodology

Formula: Cubic yards = (Length_ft × Width_ft × Depth_in ÷ 12) ÷ 27; Tons = cubic yards × 1.35

This Fill Dirt Calculator estimates how much material to order from the bed dimensions. Order ~10% extra fill dirt to allow for compaction.

  1. Measure the area length and width in feet and the depth in inches.
  2. Convert depth to feet (depth ÷ 12), then multiply length × width × depth to get cubic feet.
  3. Divide cubic feet by 27 to get cubic yards (27 ft³ = 1 yd³).
  4. Multiply cubic yards by about 1.35 to estimate the weight in tons.
  5. Add 5–10%% to cover compaction, settling and waste, then round up to the next ordering unit.

Worked example: a 20 ft × 10 ft area at 6 in deep = 100 ÷ 27 = 3.70 cubic yards, about 5.00 tons of compacted fill dirt.

Authoritative source: Wolfram MathWorld

Frequently asked questions

How do I calculate cubic yards for compacted fill dirt?
Enter the required values into the input fields and press the calculate button. The tool applies the formula Cubic yards = (Length_ft × Width_ft × Depth_in ÷ 12) ÷ 27; Tons = cubic yards × 1.35 and returns the result with a short explanation of each step, so you can check the working yourself.
How many tons are in a cubic yard of compacted fill dirt?
The Fill Dirt Calculator is free, private, and accurate: it runs entirely in your browser (no uploads, no accounts), applies the standard calculation, and explains each step so you can verify the result. Fill Dirt Calculator is a free online calculator that helps you work out fill dirt quickly and accurately, right in your browser. There is no limit on usage, and it works on any device.
How much area does one cubic yard cover?
It depends on the depth: one cubic yard covers 324 square feet at 1 inch deep, 108 square feet at 3 inches, and 81 square feet at 4 inches. The relationship is simple — divide 324 by the depth in inches. The calculator returns both the volume and the area coverage so you can match your order to the project size.
Should I order extra compacted fill dirt?
Yes — fill dirt compacts by roughly 15–25% when it is compacted in lifts, so the delivered volume settles below the ordered volume. Order 10–20% extra to compensate, and confirm whether your supplier quotes loose or compacted volume. The calculator gives the base volume; add the compaction margin on top for the practical order quantity.
Should I order extra beyond the calculated amount?
Yes — order 10–20% extra for compaction and uneven ground, since loose fill settles and the math assumes a perfect rectangular prism. Suppliers also sell by the truckload (often 10–15 cubic yards), so round up to whole loads. Running short mid-job costs more in delivery fees than the extra dirt.
How do I calculate backfill for a trench or against a foundation?
Compute the excavation volume (length × width × depth), then add 15–25% because fill compacts as you place it in 6–8 inch lifts. A 30 ft trench, 2 ft wide and 3 ft deep, is 180 cubic feet = 6.7 cubic yards — order 8 yards of compactable fill. Never backfill a foundation with topsoil; it keeps settling for years.
What's the difference between fill dirt and topsoil?
Fill dirt is subsoil — mostly clay and rock, cheap, and stable once compacted, so it's used for grading and filling holes. Topsoil is the organic top layer that plants grow in, and it weighs less (about 1.1 tons per cubic yard versus 1.35 for fill). Structure gets fill dirt; the top 4–6 inches you plant into gets topsoil.
How much soil does a raised garden bed need?
Length × width × height, straight up. A 4 × 8 ft bed filled 10 inches deep needs 4 × 8 × 0.83 = 26.7 cubic feet, right about one cubic yard — or 27 of the 1-cubic-foot bags, which is why buying bed soil in bulk is so much cheaper. Blends sold as 'raised bed mix' settle about 10% in the first season, so slightly overfill.
How many cubic yards will my dirt removal job produce?
Excavated soil expands 20–25% once it's loosened (swell), so a 10-yard hole produces 12+ yards of haul-away. Standard dump trailers carry 5–7 cubic yards and single-axle dump trucks 10–12, so quote removal on the swelled volume, not the in-ground measurement.
Is the math different for topsoil or gravel?
The volume math is identical — cubic yards = (L × W × D/12) ÷ 27 — but the weight conversion differs because densities differ: fill dirt ≈ 1.35 tons/yd³, while gravel runs ~1.5 and topsoil ~1.0–1.2. Use the tool's dirt density for subgrade fill; for decorative or drainage layers, confirm the material's actual density. Ordering by weight with the wrong density is the classic estimating mistake.
Why divide by 27?
Because a cubic yard is 3 ft × 3 ft × 3 ft = 27 cubic feet, and suppliers price and haul by the cubic yard. The tool first converts your depth from inches to feet (÷12), multiplies L × W × D for cubic feet, then ÷27 for cubic yards. Tons then come from cubic yards × ~1.35, the typical density of compacted fill dirt.
How do I measure an irregularly shaped area?
Break it into rectangles, compute each volume, and add them — or average several depth measurements for bumpy ground. For a rough circle, area ≈ 3.14 × r² works the same way. The tool assumes a uniform prism, so averaging your measurements first is what makes the estimate honest.
How accurate is the tonnage estimate?
The volume is exact for the dimensions given; the tons figure inherits the uncertainty of soil density, which varies from about 1.1 to 1.6 tons/yd³ with moisture and composition. The tool uses 1.35 as a standard mid-range value — fine for budgeting, but confirm with your supplier's scale tickets for billing. Wet clay after rain can weigh dramatically more than dry fill.

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