Fill Dirt Calculator

1. Choose how you know the area. Select "Length & width" if you measured the space, or "Known square footage" if you already calculated the area. For irregular shapes, split into smaller rectangles, calculate each one, and add the square footage together before entering.
2. Enter dimensions or area. Measure length and width in feet. For holes and low spots, measure the longest and widest points. If one section is deeper than another, treat them as separate zones and run the fill dirt calculator once for each zone.
3. Enter the fill depth in inches. Use the average depth, not the deepest single point. Measure at three or more spots across the area and average them. Use 4 to 6 inches for shallow leveling jobs and 12 to 24 inches for deep backfill.
4. Add a compaction or settling allowance. Loose fill dirt shrinks after tamping and watering. Use 15% for most backfill and leveling projects. Skip the allowance only when fill sits undisturbed, like behind a foundation wall with no compaction needed.
5. Enter density (optional). If your supplier quotes weight instead of volume, enter their tons per cubic yard density. Typical fill dirt runs 1.0 to 1.3 tons per cubic yard depending on moisture and clay content. Leave at 0 to skip the tonnage estimate.
6. Review your results. Use the cubic yards figure when ordering bulk fill dirt from a landscape supplier. The round-up line shows the nearest half yard for easy ordering. If your supplier quotes by the ton, enter their density to compare.

Pro tip: Measure depth at three different points and average them. I once ordered fill dirt based on the deepest spot in a yard and ended up with two extra cubic yards I had to wheelbarrow to the side of the house. A tape measure and three quick depth checks save money and hauling time.

This fill dirt calculator converts your project measurements into cubic yards, the standard ordering unit for bulk fill dirt. The math follows three steps: depth conversion, volume, and optional adjustment.

Volume:

Depth (ft) = Depth (in) / 12

Cubic feet = Area (sq ft) × Depth (ft)

Cubic yards = Cubic feet / 27

With compaction allowance:

Adjusted cubic yards = Cubic yards × (1 + Allowance / 100)

Weight (optional):

Tons = Adjusted cubic yards × Density (tons per cubic yard)

Variables:

• Area = project surface in square feet (length × width, or entered directly)
• Depth = average fill thickness converted to feet (divide inches by 12)
• Compaction allowance = percentage added for volume lost to tamping, settling, and watering
• Density = weight of one cubic yard of fill dirt in tons (varies by moisture and soil composition)

Example:

A 20 ft by 10 ft low spot filled 6 inches deep.

• Area = 20 × 10 = 200 sq ft
• Depth in feet = 6 / 12 = 0.5 ft
• Cubic feet = 200 × 0.5 = 100 ft³
• Cubic yards = 100 / 27 = 3.70 yd³
• With 15% compaction allowance = 3.70 × 1.15 = 4.26 yd³
• At 1.15 tons/yd³ = 4.26 × 1.15 = 4.90 tons

At that quantity, most suppliers deliver in a single dump truck load. Order 4.5 cubic yards to round up to a half-yard increment.

Quick rule: One cubic yard of fill dirt covers about 108 sq ft at 3 inches deep, or 54 sq ft at 6 inches deep. Use that to sanity-check your result.

Assumptions:

• The area has uniform depth. For uneven ground, measure at several points and use the average
• Compaction reduces loose volume by 10% to 25% depending on soil type and equipment used
• Density varies by moisture and clay content. Dry sandy fill weighs about 1.0 tons/yd³, while wet clay fill can reach 1.3 tons/yd³
• Tonnage should be confirmed with your supplier before ordering, because their material may differ from the default density
• Cost estimates use $8 to $20 per cubic yard for unscreened fill dirt in 2026, material only. Delivery adds $50 to $150 per load depending on distance