Soil Volume Calculator
Enter your bed dimensions. Results update as you type.
Estimate only. Confirm exact volume with your supplier before ordering.
Topsoil runs 10 to 55 dollars per cubic yard in bulk. Bagged soil from a hardware store works out to 54 to 162 dollars for that same yard, three to six times more for the identical volume. Get the volume wrong and you either pay for a second delivery or end up with a pile of unused bags in the garage.
The calculator above turns your bed measurements into cubic yards, cubic feet, liters, and bag counts in one step. Whether the project is a single raised bed or a new lawn, the math stays the same. Only the numbers change.
This guide covers the formula behind those numbers, how depth changes by project type, what soil costs in bulk versus bags, and the mix ratio that works best for raised beds.
On This Page
- How the Calculator Works
- Depth Guide by Project Type
- Bulk vs. Bagged: What Soil Costs
- Best Soil Mix Ratio for Raised Beds
- Mistakes That Waste Soil and Money
- Frequently Asked Questions
How the Calculator Works
For a rectangular bed, multiply length by width to get the surface area, then multiply that area by depth. Keep every measurement in the same unit before you multiply: convert inches to feet, or feet to meters, first. Divide the result by 27 to get cubic yards, since one cubic yard holds 27 cubic feet.
Example: a 10-by-10-foot bed at 2 inches deep needs 10 x 10 x (2 / 12), or about 16.7 cubic feet. Divide by 27 and the order comes to roughly 0.6 cubic yards.
For a circular bed, find the radius (half the diameter), then use the formula area = pi x radius squared. Multiply that area by depth the same way you would for a rectangle.
One more number worth keeping in your head: a cubic yard spread at a 1-inch depth covers 324 square feet. Spread at 3 inches, the same yard covers about 100 square feet. Use those two figures to sanity-check whatever the calculator gives you before you place an order.
Depth Guide by Project Type
Soil depth depends on what’s going into the ground, not on the size of the bed. Grass roots run shallow, so six inches is plenty. Carrots and potatoes push down over a foot, and skimping on depth there stunts the harvest.
| Project | Recommended depth |
|---|---|
| Topdressing an existing lawn | 0.5 to 1 in |
| New lawn or grass seed | 4 to 6 in |
| Laying sod | 2 to 4 in |
| Flower beds | 6 to 8 in |
| Vegetable and raised beds | 8 to 12 in |
| Root vegetables (carrots, potatoes) | 12 to 18 in |
Add 10 to 15 percent to whatever volume you calculate. Fresh soil compacts after the first watering and keeps settling over the following weeks, so the depth you measure on delivery day shrinks within a season.
Bulk vs. Bagged: What Soil Costs
Bulk screened topsoil runs 25 to 50 dollars per cubic yard delivered. Premium organic blends with compost mixed in run 45 to 70 dollars per yard. Most suppliers add a delivery fee of 50 to 150 dollars per load and set a minimum order of three to five yards.
Bagged topsoil costs 2 to 6 dollars per 0.75 to 1 cubic foot bag at a hardware store. Buying enough bags to fill one full cubic yard adds up to 54 to 162 dollars, several times the bulk price for the same amount of soil.
| Bag size | Bags per cubic yard |
|---|---|
| 0.75 cu ft | 36 bags |
| 1.5 cu ft | 18 bags |
| 2 cu ft | 14 bags |
Past roughly two cubic yards, bulk delivery wins on price almost every time. Below that, for a single planter or a small patch, bags stay more practical, since most suppliers won’t deliver less than three yards.
Best Soil Mix Ratio for Raised Beds
A reliable raised bed mix runs 60 percent topsoil, 30 percent compost, and 10 percent perlite or coarse sand. Topsoil supplies weight and mineral content, compost feeds the plants and improves texture, and perlite keeps the mix from compacting after repeated watering.
Square Foot Gardening’s Mel’s Mix skips topsoil entirely: equal parts compost, peat moss or coco coir, and vermiculite or perlite. The result drains fast and stays light, which suits shallow beds, though the mix costs more per cubic foot than a topsoil-based blend.
Avoid filling a bed with pure topsoil or pure compost. Straight topsoil compacts and drains poorly once boxed into a raised frame. Straight compost holds too much water and starves young roots of nitrogen while breaking down.
Calculate your bed’s total volume first, then split that number across whichever ratio you pick to know exactly how much of each ingredient to buy.
Mistakes That Waste Soil and Money
Most overorders and shortfalls trace back to one of four habits.
- Skipping the settling allowance, then running short two weeks after delivery.
- Treating an irregular bed as one shape instead of several smaller ones. Break the area into rectangles and circles, calculate each piece, then add the volumes together.
- Mixing units mid-calculation, like measuring length in feet and depth in inches without converting first.
- Filling a large bed with bagged soil instead of pricing out bulk delivery first.
Each one is an easy fix once you know to look for it.
Get the Number Right Before You Order
Volume comes from one formula: area times depth, converted to a single unit before you multiply. Depth depends on what you’re planting, from half an inch for lawn topdressing to eighteen inches for root vegetables. Bulk delivery beats bags once a project passes about two cubic yards, and a blended mix outperforms straight topsoil in any raised bed. Enter your measurements into the calculator above to get an exact number before you place an order.
Frequently Asked Questions
How many bags of soil are in a cubic yard?
A cubic yard holds 36 bags at 0.75 cubic feet each, 18 bags at 1.5 cubic feet, or 14 bags at 2 cubic feet.
Should I order extra topsoil for settling?
Yes. Order 10 to 15 percent more than your calculated volume to cover compaction after watering and natural settling over the following weeks.
What’s the difference between topsoil and garden soil?
Topsoil is unscreened native dirt with some organic matter mixed in. Garden soil and raised bed mix blend topsoil with compost and drainage amendments, which perform far better in a raised bed than topsoil alone.
Is bulk soil cheaper than bagged soil?
For any project over about two cubic yards, yes. Bulk delivered topsoil costs 25 to 70 dollars per yard, while buying enough bags to match the same volume runs 54 to 162 dollars per yard equivalent.
How deep should soil be for a vegetable garden?
In-ground vegetable beds need 6 to 8 inches of soil. Raised beds need 8 to 12 inches, and root vegetables like carrots and potatoes need 12 to 18 inches.
