Topsoil Calculator
Instantly calculate how much dirt you need for your landscaping project. Convert your area and depth into the exact number of cubic yards, tons, and bags of topsoil required.
Whether you are establishing a new lawn, filling a raised garden bed, or topdressing existing grass, figuring out exactly how much topsoil or fill dirt you need can be confusing. Ordering a bulk delivery of cubic yards is often much cheaper, but buying 40lb bags at a big box store is more convenient for small garden patching.
Our topsoil calculator solves this problem instantly. By entering your project’s square footage and desired depth, you can calculate the total volume in cubic feet, easily converting it into the exact number of cubic yards, tons, or retail bags required.
How to Calculate How Much Topsoil You Need
Topsoil and dirt are sold by volume, not flat area. To calculate your required volume, you must convert the two-dimensional square footage of your project into a three-dimensional measurement using your desired depth.
- Determine the Square Footage: Measure the length and width of your garden bed or lawn space in feet. Multiply them together (Length × Width = Area). For example, a 10 ft by 20 ft space is 200 sq ft.
- Convert Depth to Feet: Soil depth is usually measured in inches, but volume requires feet. Divide your desired depth in inches by 12. For example, 4 inches ÷ 12 = 0.333 feet.
- Calculate Cubic Feet: Multiply your Area (sq ft) by your Depth (in feet). 200 sq ft × 0.333 ft = 66.6 cubic feet.
- Convert to Cubic Yards: There are 27 cubic feet in one cubic yard. Divide your total cubic feet by 27. (66.6 ÷ 27 = 2.46 cubic yards).
Topsoil Calculator Formula
Cubic Yards = (Area in sq ft × (Depth in inches ÷ 12)) ÷ 27
Bags = Total Cubic Feet ÷ Bag Size (e.g., 0.75)
Cubic Yards vs. Tons vs. Bags
Once you calculate your volume, you must decide how to buy it. Understanding the difference between volume (yards), weight (tons), and packaging (bags) will help you make the most cost-effective choice.
- Cubic Yards (Volume): This is the standard unit for bulk delivery. One cubic yard is a block of dirt 3 feet long, 3 feet wide, and 3 feet high.
- Tons (Weight): Depending on moisture content and organic matter, one cubic yard of topsoil weighs approximately 1.0 to 1.2 tons (2,000 to 2,400 lbs). Heavy, wet clay soil will weigh more than light, dry, sandy loam.
- Bags (Retail): Standard bags of topsoil at home improvement stores generally weigh 40 lbs. However, because soil density varies, a 40 lb bag usually contains between 0.5 and 0.75 cubic feet of actual material. You need roughly 36 to 54 bags to equal a single cubic yard.
Topsoil Coverage Chart
If you prefer a quick reference without doing the math, use this soil yardage calculator chart. It shows how many square feet a specific amount of dirt will cover based on the depth.
| Amount of Topsoil | Coverage at 1″ Depth | Coverage at 2″ Depth | Coverage at 4″ Depth |
|---|---|---|---|
| 1 Bag (0.75 cu ft) | 9 sq ft | 4.5 sq ft | 2.25 sq ft |
| 1 Cubic Yard | 324 sq ft | 162 sq ft | 81 sq ft |
| 3 Cubic Yards | 972 sq ft | 486 sq ft | 243 sq ft |
| 5 Cubic Yards | 1,620 sq ft | 810 sq ft | 405 sq ft |
| 10 Cubic Yards | 3,240 sq ft | 1,620 sq ft | 810 sq ft |
Settling and Waste: Why You Need Extra
The 10% Settling Rule
Freshly delivered topsoil is loose and aerated. Once you spread it, walk on it, and water it (or wait for the first heavy rain), the soil will compress and settle. If you order the exact mathematical volume you calculated, your final soil level will be too low.
To avoid coming up short, professional landscapers and university extension offices strongly recommend adding a 10% to 15% settling and waste factor to your total order. If you are filling deep raised beds (8 inches or more), a 15% to 20% factor may be necessary.
Common Topsoil Projects & Depths
Choosing the correct depth is critical for plant health and avoiding unnecessary expense. Here are common guidelines:
- Topdressing a Lawn (¼ to ½ inch): Spreading a thin layer of topsoil or a 50/50 topsoil-compost blend over existing grass helps improve soil structure and smooth out minor divots without smothering the grass.
- Overseeding a Lawn (¼ inch): A very thin layer of soil gives new grass seed excellent seed-to-soil contact and protects it from birds.
- Establishing a New Lawn (4 to 6 inches): If you are laying sod or planting seed on bare, poor subsoil, you need a minimum of 4 inches of high-quality topsoil to ensure healthy root development.
- Filling Raised Beds (8+ inches): When filling a contained raised bed, avoid using 100% topsoil, as it can become compacted and drain poorly. Use a blend of topsoil, compost, and coarse sand or perlite.
Frequently Asked Questions (FAQ)
Multiply the length and width of your area in feet to get square footage. Multiply that by your desired depth in feet (inches divided by 12) to find total cubic feet. Finally, divide by 27 to convert your total into cubic yards for bulk ordering.
A standard 40 lb bag of topsoil typically yields about 0.75 cubic feet of volume. Spread at a standard depth of 2 inches, one 40 lb bag will cover approximately 4.5 square feet.
Depending on the size of your wheelbarrow, 1 cubic yard of topsoil equals roughly 9 to 14 full loads. A standard homeowner wheelbarrow holds about 2 to 3 cubic feet of material, and there are 27 cubic feet in a yard.
Because 1 cubic yard of topsoil weighs roughly 1.2 tons, 1 ton equals about 0.83 cubic yards. Spread at a depth of 3 inches, 1 ton of topsoil will cover approximately 89 square feet of ground.
It is almost always significantly cheaper to buy topsoil in bulk by the cubic yard, provided you need more than 1 or 2 yards. Even factoring in a delivery fee, a bulk truckload will cost far less per cubic foot than purchasing 40 individual plastic bags from a hardware store.
Volume-wise, yes; 1 cubic yard easily fits into a standard pickup bed. However, 1 yard of moist topsoil can weigh between 2,000 and 2,400 lbs, which exceeds the safe payload capacity of most half-ton (1500 series) trucks. You generally need a 3/4-ton or 1-ton truck to safely haul a full yard of dirt.
A standard tandem-axle dump truck hauls between 10 and 15 cubic yards of topsoil. Depending on the soil quality (screened vs. unscreened) and local delivery rates, a full dump truck load typically costs between $150 and $500.
A pile of 10 cubic yards of topsoil is roughly the size of a standard minivan or a large SUV. If dumped in a conical mound in your driveway, the pile will be approximately 10 to 12 feet wide at the base and 4 to 5 feet tall.
A modern Ford F-150 has a maximum payload capacity between 1,500 and 3,300 lbs depending on the specific configuration and engine. Because a cubic yard of topsoil averages 2,200 lbs, most standard F-150s can safely haul roughly 0.75 to 1 cubic yard of dirt per trip.
Reference: https://en.wikipedia.org/wiki/Mulch