Topsoil Calculator
Work out how much topsoil a job really takes with this topsoil calculator. Pick the shape, type the size and the depth, and read the full order in one result. The tool shows cubic yards to order with a settling allowance added, the weight in tons, the bag count, and the bag route and bulk route costs side by side. It suits new lawns, garden beds and raised beds.
What the result numbers mean
Your volume with the settling allowance added. Soil drops after watering, so the order number plans for the finished level.
Yards turned into weight at about 1.1 tons per yard. Use it to judge truck trips and trailer loads for a bulk order.
The same order in bags of your chosen size. The count shows fast when bags stop making sense for a job.
The bare math of the shape at your depth. The gap between this number and the order is your settling margin.
Add a price per bag and the tool prices the full bag count for this exact area.
Add a price per cubic yard and the tool prices bulk. Past about 2 yards, bulk usually wins on price and trips.
How much topsoil do I need?
Multiply the length by the width by the depth in feet, then divide by 27. A lawn area 20 by 10 foot at 4 inches deep holds 2.47 cubic yards, about 2.7 tons. Add a settling allowance on top, or the level sinks in the first weeks.
How the math works
Choose a rectangle for lawns and beds. Choose a circle for a round bed or a tree surround.
Type the length and the width in feet. A yard with beds in many spots runs one area at a time, then adds the yards.
Depth follows the job. Top dressing takes 2 inches. A new lawn base takes 4 to 6. A raised bed takes 12 or more.
The tool multiplies length by width by depth for cubic feet, then divides by 27. Yards are the unit bulk yards sell by.
Cubic feet / 27Loose soil packs down after watering and rain. The allowance, 10 percent to start, keeps the finished level where you planned it.
The tool weighs the order at about 1.1 tons per yard, counts bags at your bag size, and prices both routes when you add prices.
Yards x 1.1 tonsA new lawn base, 20 by 10 foot at 4 inches deep
Here is the lawn from the quick answer, on a breakdown slip, the way the tool builds it.
Read the slip top to bottom. The raw volume is the bare shape at depth. The settling line is the drop the soil will take after watering. The order total is the number you give the yard, in yards, tons or bags.
Shapes and depths, explained
This topsoil calculator turns shape and depth into one order with the settling already planned. The depth follows the job the soil must do. Tap a card to load it in the tool.
Lawns, beds and most yards. Measure the length and the width in feet. Split an odd yard into rectangles and run each part.
Key measure: length and width in feetTap to load in the calculatorRound beds and tree surrounds. Measure straight across the middle for the diameter the formula needs.
Key measure: diameter across the middleTap to load in the calculatorA thin skin over a living lawn. Two inches feeds the roots and levels small dips without burying the grass.
Key measure: depth 2 inTap to load in the calculatorFresh soil under new seed or sod. Four inches is the working base. Six suits poor ground that needs a full fresh start.
Key measure: depth 4 to 6 inTap to load in the calculatorA framed bed fills deep. Twelve inches or more, laid in layers with a raised bed mix, gives roots a full season of room.
Key measure: depth 12 in in layersTap to load in the calculatorLoose soil holds air. Water and rain push the air out and the level drops. The settling allowance in the result plans for that drop.
Key measure: about 10 percentWhat topsoil is made of
Topsoil is the top layer of ground soil, the part roots live in. A typical composition by volume runs about 45 percent mineral matter, about 5 percent organic matter, and about 50 percent air and water held in the pores.
Good loam splits its mineral part near 40 percent sand, 40 percent silt and 20 percent clay. Placed topsoil specs ask for at least 1.5 percent organic matter. Better soil carries more, and the dark color shows it.
Soil amendment basics
To amend soil means to mix good material into it. Compost is the usual pick for tired beds. Spread 2 to 3 inches over the bed and work it into the top 6 to 8 inches. That mix lands near a quarter to a third compost in the worked layer.
Calculating soil amendment runs by volume first. One inch over 1,000 square feet takes about 3.1 cubic yards. Run your own bed through the tool at the spread depth to size the order. By weight, a cubic yard of compost runs about 1,000 pounds, and moisture swings that number a lot.
Topsoil vs potting soil, tonne vs ton
Two mix ups cost buyers money every season. Both take ten seconds to avoid.
Topsoil versus potting soil
What's the difference? Topsoil is real ground soil for beds, lawns and grading. Potting soil is a bagged mix for pots, and many mixes hold no soil at all, just peat or coir, bark and perlite. Per yard it costs far more than topsoil. Fill beds with topsoil and save potting mix for containers.
Tonne vs ton
A ton on this page means the US ton of 2,000 pounds. A tonne is the metric unit of 1,000 kilograms, about 2,205 pounds. One tonne equals about 1.10 US tons. Check which unit a supplier quote uses before you compare prices.
Calculating irregular shapes
Split an odd bed into rectangles and circles on paper. Run each part through the tool and add the yards together. A curve counts as a circle or a half circle.
The split method beats one rough guess on any bed with bends. It also shows you which part of the yard eats the most soil.
Topsoil numbers, in one place
| Job | Depth |
|---|---|
| Lawn top dressing | 2 in |
| New lawn base | 4 to 6 in |
| Raised bed fill | 12 in or more, in layers |
Common mistakes
The lawn sinks below the plan height within a few weeks. Ten percent extra in the order is cheaper than a second delivery.
Fill dirt fills holes. Grass roots want screened topsoil with life in it. Buy the soil the job needs, not the cheap pile.
Past about 2 yards, one bulk load wins on price and on trips. Read the bag count here before you choose the route.
Two inches dresses a lawn and 12 fills a raised bed. A guessed depth starves one job or buries the other. The job picks the number.
How to buy topsoil for your job
The result moment is the buying moment. Use the yards and the bag count from this topsoil calculator at the shelf or on the phone with the yard. Two routes cover almost every job.
Option A: The bag route
- Bags hold 1 or 1.5 cubic feet. The tool counts them at your chosen size.
- Bagged soil stays clean in a car and stores dry for the next bed.
- Screened bagged soil suits beds where roots start at once.
- The cost per yard climbs fast in bags. Check the count before you commit.
Option B: Bulk screened topsoil
- Ask for screened topsoil for lawns and beds. Plain fill dirt is a different product.
- Ask for the full price with delivery. One load beats many car trips.
- Pick the drop spot on a hard surface near the job. Soil moves by the barrow load.
- Cover the pile when rain threatens. Wet soil weighs far more per barrow.
For the mulch that covers a finished bed, the mulch calculator gives yards and bags in the same style. For a gravel base or a path, the gravel calculator weighs the job by type.
Questions, answered
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