CalcaTools

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.

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

ft
ft
in
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

functions Shows the working, not just the answer

For students and teachers, the final number is only half the value. Every math tool here exposes the formula it applied, the intermediate steps, and the rounding rule, so you can follow along, check your homework, or use the answer in a proof or report with confidence.

calculate Accurate to the spec

Calculations use 64-bit floating point with sensible rounding for the domain (currency to 2 decimals, percentages to 4 decimals, algebra to 6 significant figures). Where exact rational arithmetic matters — fractions, factorials, simplification — we use a dedicated BigNumber path so 1/3 + 1/6 returns ½, not 0.49999.

school Free for classroom use

Educators are welcome to link to any math calculator on CalcaTools from a class site, Google Classroom, or worksheet. The pages are mobile-friendly, free, ad-supported (so we can keep them free) and have no sign-up wall — students just click and use them in class or at home.

tips_and_updates Pair with the spoke articles

Below the calculator we link a small set of plain-English explainer pages — "What is a percentage?", "Why does PEMDAS matter?", and so on. They cover the underlying concept in 4–6 short paragraphs. Read those before the calculator if the topic is new, or after if you want the extra context.

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.

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.

Frequently asked questions

How do I calculate cubic yards for compacted fill dirt?
Multiply length (ft) × width (ft) × depth (ft), then divide by 27. Enter depth in inches and the calculator converts it for you (depth ÷ 12).
How many tons are in a cubic yard of compacted fill dirt?
A cubic yard of compacted fill dirt weighs roughly 1.35 tons, though the exact figure varies with moisture and stone size.
How much area does one cubic yard cover?
One cubic yard covers about 324 sq ft at 1 inch deep, 108 sq ft at 3 inches, or 54 sq ft at 6 inches. Order ~10% extra fill dirt to allow for compaction.
Should I order extra compacted fill dirt?
Yes — add about 5–10%% for compaction, settling, uneven ground and spillage so you don't run short mid-project.
Is the Fill Dirt Calculator free to use?
Yes. It is completely free, needs no sign-up, and every calculation runs in your browser so your measurements stay private.
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.

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