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 results.
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, run this dirt calculator once for each zone and add the totals.
3. Enter dirt depth in inches. Use the average depth, not the deepest single point. Measure at three or more spots and average them. Use 2 to 4 inches for garden topping, 6 to 12 inches for leveling and raised bed fill, and 12+ inches for deep fill.
4. Set a waste or compaction allowance. Dirt shrinks after settling and compaction. Use 10% for garden beds and light fill. Use 15% to 20% for backfill that will be tamped. Skip the allowance only when the fill sits undisturbed.
5. Choose a bulk density. Fill dirt averages about 1.15 tons per cubic yard. Loose, dry dirt is closer to 0.90 tons per cubic yard. If your supplier quotes a specific density, choose "Custom" and enter their number.
6. Enter bag size (optional). If you plan to buy bagged dirt from a hardware store, enter the bag volume in cubic feet. Common bags are 0.75, 1.0, or 1.5 cubic feet. The dirt calculator will show how many bags you need.
7. Review your results. Use the cubic yards figure when ordering bulk dirt. The round-up line shows the nearest half yard for easy ordering. If your supplier quotes by the ton, use the estimated tons instead.

Pro tip: Measure depth at three different points and average them. I once ordered dirt based on the deepest corner of a low spot and ended up with nearly two extra cubic yards piled in the driveway. Three quick depth checks with a tape measure save money and hauling time.

This dirt calculator converts your project measurements into cubic yards, the standard ordering unit for bulk dirt. Use it as a dirt volume calculator and dirt yardage calculator in one step. The math follows three steps: depth conversion, volume calculation, and order adjustment.

Volume:

Depth (ft) = Depth (in) / 12

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

Cubic yards = Cubic feet / 27

Order quantity:

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

Weight:

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

Variables:

• Area = project surface in square feet (length × width, or entered directly)
• Depth = average dirt thickness converted to feet (divide inches by 12)
• Allowance = percentage added for waste, settling, or compaction loss
• Density = weight of one cubic yard of dirt in tons (fill dirt ~1.15, loose dirt ~0.90)

Example:

A 12 ft by 8 ft garden bed filled 6 inches deep.

• Area = 12 × 8 = 96 sq ft
• Depth in feet = 6 / 12 = 0.5 ft
• Cubic feet = 96 × 0.5 = 48 ft³
• Cubic yards = 48 / 27 = 1.78 yd³
• With 10% allowance = 1.78 × 1.10 = 1.96 yd³
• At 1.15 tons/yd³ = 1.96 × 1.15 = 2.25 tons

Most local suppliers deliver in half-yard increments, so you'd order 2.0 cubic yards for this job.

Quick rule: One cubic yard of 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 before ordering.

Recommended depth by project type:

Assumptions:

• The area is roughly rectangular. For irregular shapes, split into smaller sections and add the volumes
• Depth is the average across the project area. Uneven ground can throw off estimates if you only measure one spot
• Fill dirt density varies by moisture and clay content. Dry sandy dirt weighs about 0.90 tons/yd³, while wet clay-heavy fill can reach 1.3 tons/yd³
• Compacted dirt loses 10% to 25% of its loose volume depending on soil type and equipment used
• For raised bed dirt, most gardeners use a mix of topsoil, compost, and amendments rather than straight fill dirt. This dirt calculator estimates volume only, not soil blend ratios
• Cost estimates use $8 to $25 per cubic yard for unscreened fill dirt in 2026, material only. Delivery adds $50 to $150 per load depending on distance