What Is the Fill Dirt Calculator?
Fill dirt is soil used to raise the grade of a site, backfill a foundation, level a yard, or build up low spots. This calculator tells you how much fill dirt to order by computing the volume of your project in cubic yards, the approximate weight in tons, and an optional total cost. Suppliers usually sell dirt by the cubic yard or by the ton, so knowing both figures helps you order the right amount and compare prices.
How to Use It
Enter the length and width of the area in feet and the desired fill depth in inches. Provide the material density (fill dirt is typically about 1.3–1.5 tons per cubic yard; the default is 1.45). Optionally add a price per cubic yard to estimate the cost. The calculator returns cubic yards, tons, total cubic feet, and cost.
The Formula Explained
Volume is length × width × depth, but depth is entered in inches, so it is divided by 12 to convert to feet. The result is in cubic feet, which is divided by 27 (the number of cubic feet in a cubic yard) to give cubic yards: $$V = \frac{L \times W \times \dfrac{D}{12}}{27}$$ Weight is volume × density: $$\text{tons} = V \times \rho$$
Worked Example
For a 20 ft × 10 ft area filled to 6 inches deep with dirt at 1.45 tons/yd³: depth = \(6/12 = 0.5\) ft, volume = \(20 \times 10 \times 0.5 = 100\) cubic feet = \(100 \div 27 \approx 3.70\) cubic yards. Weight = \(3.70 \times 1.45 \approx 5.37\) tons.
FAQ
How much does a cubic yard of fill dirt weigh? Roughly 1.3 to 1.5 tons when dry, but moisture and compaction can raise this to 1.7+ tons.
Should I order extra? Yes—add 5–10% for compaction and settling, especially for structural fill.
What's the difference between fill dirt and topsoil? Fill dirt is subsoil with little organic matter, ideal for grading and structural support; topsoil is for planting.
