How to use the Dirt Calculator
- Measure the plan and uniform depth.Choose Rectangle, Known Area, Circle or Triangle. Triangle height is perpendicular to its base. Split irregular sites or varying depths into separate sections and add their volumes.
- Keep assumptions visible.Extra allowance starts at 0%. Density, truck capacity and price start blank. Enter only the assumptions you have confirmed for your project.
- Read quantity before loads.Project volume includes any entered extra. Volume-based truckloads and cost work without density; density adds an estimated weight only.
Cubic yards measure the space.
For a rectangle, cubic feet = length in feet × width in feet × (depth in inches ÷ 12). Cubic yards = cubic feet ÷ 27. Known Area uses square feet × depth in feet. Circle uses π × (diameter ÷ 2)², and Triangle uses ½ × base × perpendicular height before multiplying by depth.
In Metric, square meters × (depth in centimeters ÷ 100) gives cubic meters. One cubic yard equals 0.764554857984 cubic meters. Switching unit systems converts your measurements and preserves the physical volume.
Extra volume and estimated dirt weight
Extra = geometric volume × allowance percentage ÷ 100. Project volume = geometric volume + extra. This visible allowance is not a compaction model; confirm any placement requirements separately.
There is no universal dirt density. Material composition, moisture, voids and condition can change bulk density. Use a supplier's density for the material you plan to handle. Estimated short tons = project cubic yards × entered short tons per cubic yard; estimated kilograms = project cubic meters × entered kilograms per cubic meter.
Density is blank by default and no presets are published. A custom entry is not independently verified. Weight appears only with a valid entered density; volume stays available without it.
Estimating truckloads of dirt
Volume truckloads = project cubic yards ÷ entered cubic yards per truck, or project cubic meters ÷ entered cubic meters per truck. Whole trucks = round up(exact load count). For a project of 13.2 yd³ and a user-entered 10 yd³ capacity, that is 1.32 loads and 2 whole trucks.
No truck size is assumed. Ask your hauler for the usable volume capacity for the material and trip, accounting for the vehicle's weight limit separately. This volume estimate does not check payload or legal transport limits. Blank capacity produces no truckload result.
Optional material cost = project volume × entered price per cubic yard or cubic meter. Whole-truck rounding does not inflate volume or cost. Delivery, tax, fuel surcharges and supplier minimums are not included.
20 ft × 12 ft × 6 in
Depth: 6 in ÷ 12 = 0.5 ft. Volume: 20 × 12 × 0.5 = 120 ft³. Cubic yards: 120 ÷ 27 = 4.444444… yd³, displayed as 4.44 yd³. With 0% extra, project volume is the same.
Suppose you enter a capacity of 3 yd³ per truck. Using the full-precision volume, 4.444444… ÷ 3 = 1.481481… loads, displayed as 1.48. Round upward to 2 whole trucks. The displayed 4.44 is not fed back into the calculation.
3 yd³ is only a user-entered example capacity, not a recommended or standard dump-truck size. The calculator leaves capacity blank until you enter your own.
Dirt vs topsoil vs fill dirt
Generic quantity and volume: use this Dirt Calculator. Planting or lawn soil: the Topsoil Calculator handles lawn, garden and planting quantity with optional bags, bulk and cost. Grading or backfill: The Fill Dirt Calculator separates target in-place fill from optional user-entered loose-order volume, then plans trucks and quotes from order volume. Soil and Garden Soil remain separate future intents.
For material-neutral volume, use the Cubic Yard Calculator. Gravel Calculator and Rock Calculator handle their own materials. The Sand Calculator handles sand quantity and purchasing; Fill Dirt owns the separate grading/backfill target and order-volume workflow.
Dirt calculator FAQ
How many cubic yards of dirt do I need?
Multiply the measured plan area by uniform depth in compatible units, then convert cubic feet to cubic yards by dividing by 27. Add an optional allowance only when your project calls for it.
Can I estimate loads without dirt density?
Yes. Enter a usable volume capacity per truck. Density is only needed for estimated weight; mass-based truck capacities and prices are not modeled by this calculator.
Why show fractional loads and whole trucks?
The fractional count describes quantity divided by capacity. Whole trucks round that count upward to plan trips, while project volume and material cost retain their original quantities.
Does extra allowance account for compaction?
No. It adds a visible percentage to geometric volume. For a separately entered target-to-loose-order relationship, use the Fill Dirt Calculator. It assumes no compaction factor or percentage.
What happens when I switch Imperial and Metric?
Dimensions, depth, density, volume capacity and price are converted together. The same physical project, load counts and equivalent material cost are preserved. Short tons and metric tonnes remain distinct mass units.