Free calculator
Fill Dirt Calculator
Use this fill dirt calculator to estimate cubic feet, cubic yards, optional tons, and a simple cost placeholder from length, width, depth, density, and waste. The printable material list is built for filling low spots and raising rough grade before you order bulk fill.
EstimateEstimate only for material volume; fill dirt is unscreened subsoil, not planting soil or structural fill. Local conditions vary. Consult a professional for structural or safety questions.
Project inputs
Estimate
6.11 cubic yards of fill dirt
Filling 300 sq ft to 6 inches needs about 6.11 cubic yards, or 7.33 tons, of fill dirt after a 10% allowance.
Printable material list
Estimate- Fill dirt6.11 cu yd10% extra for settling and compaction
- Fill dirt by weight7.33 tons1.2 tons/cu yd assumption
- Bulk cost placeholder$109.98$18/cu yd assumption
- Screened top soilseparateadd a planting layer on top if you will grow on it
Estimate only. Fill dirt is unscreened subsoil; structural fill behind walls, under footings, or for load-bearing grade needs a qualified professional and compaction testing.
Visible defaults
Assumptions
- Cubic yards equal cubic feet divided by 27.
- Default depth is 6 inches and waste defaults to a planning cushion.
- Optional density defaults to about 1.2 tons per cubic yard for loose fill.
- Fill dirt here is unscreened subsoil for grading, not planting soil or structural fill.
Math
Calculation details
- Area = length x width.
- Cubic feet = area x depth in feet.
- Cubic yards = cubic feet / 27.
- A waste allowance covers settling and compaction.
What this fill dirt calculator does
Fill dirt is usually sold bulk by the cubic yard or by the ton on a delivery ticket, so a measured low spot needs to become a volume before you can order. This calculator takes the footprint, depth, density, and waste, then converts the same volume into cubic feet, cubic yards, optional tons, and a plain cost placeholder you can carry to a supplier.
It is built for raising a sunken area, backfilling around a project, leveling a rough yard, or filling a washed-out section before finish grading. It does not decide whether fill dirt is the right material, and it makes no structural or safety call. It simply turns a measured space into an honest shopping estimate with the assumptions visible.
How deep and how to measure fill dirt
Fill dirt is unscreened subsoil. It carries clay, rock, and roots, which is fine for bulking up grade but wrong for planting. Measure the average depth of the gap you are filling, not the deepest pocket. A 6 inch default suits many leveling jobs, but a sunken area can vary from 2 inches at the edges to a foot or more in the middle.
For an uneven hole, split it into zones and average the depth, or calculate each zone and add the results. Length times width gives square feet; depth in inches sets how fast that area turns into yards. Marking the area with stakes and a string line before measuring keeps the estimate closer to what the truck actually dumps.
Formula used
The calculator multiplies length by width to get square feet, converts depth from inches to feet, then multiplies to get cubic feet. Cubic yards are cubic feet divided by 27. Optional tons are cubic yards multiplied by the density you enter, and the cost placeholder multiplies cubic yards by your price per cubic yard.
For example, a 20 by 15 foot area at 6 inches deep is 150 cubic feet, or about 5.6 cubic yards before waste. At a planning density near 1.2 tons per cubic yard, that is roughly 6.7 tons. Fill dirt settles and compacts, so the waste cushion helps the order match the finished grade rather than the loose pile.
Bulk fill versus bagged dirt
Fill dirt is almost always a bulk material. It is rarely worth bagging because the volumes are large and the dirt is cheap compared with the handling. Most projects that need real fill are sized in cubic yards and arrive by dump truck, so the cubic yard and ton outputs are the numbers that matter when you call a yard.
The optional cost field is intentionally simple. It multiplies cubic yards by your entered price and ignores delivery, spreading, minimum loads, taxes, and the labor of moving dirt across a yard. Delivery and a place to dump often cost more than the dirt itself, so treat the placeholder as a comparison tool, not a supplier price.
Common mistakes
The biggest mistake is confusing fill dirt with top soil. Fill dirt is unscreened subsoil for bulking up grade and will not grow a lawn or garden. If you plan to plant on top, order a separate cap of top soil and estimate that layer on its own page. Another mistake is using square feet as if it were volume; depth always matters.
Forgetting compaction is also common. Loose fill settles after rain, traffic, and time, so a low spot filled exactly to grade today can sink later. A modest waste cushion and a second check after the first settling pass are safer than ordering the bare minimum and coming up short.
Before you order
Take the printed list, your measured dimensions, and a note on access to the supplier. Ask whether they sell by the yard or ton, what their fill dirt contains, and whether it is screened. If their density or coverage differs from the defaults, enter the local numbers so the order matches the real material. Critically, this estimate covers volume only.
If the dirt will sit behind a retaining wall, under footings, against a foundation, or anywhere it must carry a load or hold grade reliably, that is structural fill. Structural fill needs a qualified professional, engineered specification, and compaction testing. This calculator does not size or approve that work; use it only for rough volume planning.
Quick reference
Fill dirt coverage by depth
| Depth | Coverage per cubic yard | Coverage per ton |
|---|---|---|
| 2 in | 162 sq ft | 135 sq ft |
| 4 in | 81 sq ft | 68 sq ft |
| 6 in | 54 sq ft | 45 sq ft |
| 12 in | 27 sq ft | 23 sq ft |
Based on 1 cubic yard = 27 cubic feet and a planning density near 1.2 tons per cubic yard. Supplier density and moisture vary.
FAQ
Fill Dirt Calculator FAQ
How do I calculate fill dirt needed?
Multiply length by width to get square feet, multiply by depth in feet to get cubic feet, then divide by 27 for cubic yards. Add a waste cushion for settling, and multiply by density for an optional ton estimate.
What is the difference between fill dirt and top soil?
Fill dirt is unscreened subsoil for bulking up grade and filling low spots. It is not meant for planting. Top soil is screened for growing grass and gardens. Many projects use fill dirt below a thin top soil cap.
How many cubic yards of fill dirt do I need?
Divide total cubic feet by 27. A 20 by 15 foot area at 6 inches deep is 150 cubic feet, or about 5.6 cubic yards before waste. Add a settling cushion before ordering.
How many tons is a cubic yard of fill dirt?
A common planning value is about 1.2 tons per cubic yard for loose fill, but moisture and soil type change the weight. Use the supplier conversion when you order by the ton.
Can I use fill dirt as structural fill?
No determination here. Structural fill behind walls, under footings, or for load-bearing grade needs a qualified professional, an engineered specification, and compaction testing. This calculator estimates volume only and makes no safety call.
Does fill dirt need to be compacted?
Loose fill settles after rain, traffic, and time. For general leveling, a waste cushion and a second pass help. For any load-bearing or structural use, compaction and testing should be handled by a professional.
Methodology
Who built and reviewed this estimate
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