Dirt Calculator
With a dirt calculator you easily calculate how much dirt, fill dirt, or topsoil you need for your garden, raised bed, or landscaping project.
You just need to enter:
- Length
- Width
- Depth
And the calculator will give you:
- Cubic feet
- Cubic yards
- Number of bags
- Total weight in tons
How Much Dirt or Topsoil You Need
When you are starting a garden project or planning a landscaping area, one of the most important things is to know how much soil you need.
In case you want to:
- Fill a raised bed
- Level your yard
- Refresh your garden soil
You must calculate the exact quantity.
"what I want to specifically discuss is, how to calculate exactly how much soil you should buy"
If you don’t calculate properly:
- You may buy too much and waste money
- Or buy too little and stop your project halfway
Why Accurate Soil or Dirt Calculation is Important
When you use the correct amount of soil, it will save both time and money.
Also, soil does not stay at the same level forever.
when you fill up your beds the first time it rains it's going to compact the soil a bit.
This means:
- Soil settles after rain
- Air gaps reduce over time
- You may need to add more soil later
That’s why it’s smart to slightly overestimate.
Also Check: Mulch Calculator
How to Measure Soil Volume
To calculate soil volume, you need three basic measurements:
- Length
- Width
- Depth
The formula is simple:
Volume = Length × Width × Depth
it's a simple calculation of the width of the bed times the length of the bed times the depth of the bed.
Important Tip About Units
You cannot mix units while calculating.
you can't multiply inches and feet together you have to keep similar units.
So always convert:
- Inches → Feet
- cm → meters
- etc.
Example Calculation (Raised Bed)
Let’s take a real example:
- Width = 4 feet
- Length = 10 feet
- Depth = 8 inches
Convert depth into feet:
8 inches = 8/12 feet
Now calculate:
4 × 10 × (8/12) = 26.67 cubic feet
That will get you 26.67 cubic feet per bed
Convert to cubic yards:
26.67 ÷ 27 = 0.98 cubic yards
We're just going to round that up to these beds are exactly one cubic yard each.
Bulk Dirt vs. Bagged Dirt
For small projects, bagged dirt (the terms "bagged dirt" and "bagged soil" are used interchangeably here) works fine. For large projects, bulk dirt delivered by the truckload is far more practical and considerably cheaper than buying individual bags.
Example:
- 214 cubic feet of dirt needed
- Each bag = 1 cubic foot
That means:
- 214 bags of dirt needed
At a typical bagged price, that works out to roughly 856 dollars in bagged dirt. Ordering the same amount in bulk typically costs less than half that, since you are paying for delivery and volume instead of individual packaging.
Why It's Smart to Order a Little Extra
On larger projects, it's common to round your calculated amount up rather than order the exact number. This is important because:
- Soil compacts
- Some soil gets wasted
- Extra soil is always useful
How Much Dirt Do You Need
| Area Size (ft) | Depth (in) | Cubic Feet | Cubic Yards | Bags (1 cu ft) |
|---|---|---|---|---|
| 4 × 4 | 6 | 8 | 0.30 | 8 |
| 4 × 8 | 6 | 16 | 0.59 | 16 |
| 4 × 10 | 8 | 26.67 | 0.98 | 27 |
| 5 × 10 | 12 | 50 | 1.85 | 50 |
| 10 × 10 | 6 | 50 | 1.85 | 50 |
Soil Measurement in Tons
Different materials have different weights:
- Topsoil → ~2100 lbs per cubic yard
- Fill dirt → ~2200 lbs
- Sand → ~2600 lbs
- Compost → ~1200 lbs
To convert into tons:
Tons = (Cubic Yards × Density) ÷ 2000
How to Measure Dirt by the Yard
"A yard of dirt" means one cubic yard — a cube 3 feet long, 3 feet wide, and 3 feet deep, which works out to 27 cubic feet. That's true no matter what material you're measuring: dirt, topsoil, sand, or compost. What changes between materials is the weight, not the size.
Using fill dirt's typical weight (about 2,200 lbs per cubic yard), here's what common yard amounts weigh:
| Yards of fill dirt | Approx. weight |
|---|---|
| 6 cubic yards | ~6.6 tons |
| 8 cubic yards | ~8.8 tons |
| 14 cubic yards | ~15.4 tons |
| 16 cubic yards | ~17.6 tons |
| 200 cubic yards | ~220 tons |
For other materials, swap in that material's density from the list above and use the same formula: tons = (cubic yards × density) ÷ 2,000.
One cubic yard also equals 27 one-cubic-foot bags, or fewer bags if you're buying larger sizes — divide 27 by your bag's cubic footage to get the count.
If you're getting dirt from a loader or skid-steer "scoop" rather than a measured delivery, know that scoop size varies a lot by machine and operator — commonly somewhere in the 0.5 to 1.5 cubic yard range — so confirm the actual bucket capacity with whoever is loading it rather than assuming a standard size.
Important Tip About Shape
The formula we used works only for simple shapes.
That calculation is only valid if your beds are rectangular or square.
If your area is:
- Circular
- Triangular
- Irregular
Then you must use a different formula.
Why Local Soil is Better
Stuff that you buy locally is generally better quality than what you get from mass-market sellers.
Also:
I like to support local businesses.
So if possible:
- Buy local soil
- Get better quality
- Save money
Topsoil vs. Fill Dirt: What's the Difference?
The two are often confused, but they serve different purposes. Topsoil is the nutrient-rich upper layer of soil that supports plant growth — it is what you want for planting beds, lawns, and gardens. Fill dirt is subsoil dug up from lower layers, with little to no organic content, and it is not meant for growing anything.
For the full breakdown, read our guide to what topsoil is, including how it compares with fill dirt.
Fill dirt is what you want for grading a yard, leveling low spots, or building up a base under a patio or shed — projects where compaction and stability matter more than fertility. Using fill dirt where you actually need topsoil (or the reverse) is one of the most common and costly mistakes in a soil-buying project, since the two are priced and sold differently and are not interchangeable.
Frequently Asked Questions
Multiply length × width × depth and convert into cubic yards.
Divide total cubic feet by your bag size in cubic feet, then round up. The math is identical whether you call it bagged dirt or bagged soil — it is the same volume either way.
Yes, a little. Soil settles and compacts over time, especially after rain, so ordering 5–10% more than your calculated amount avoids a second trip.
Yes. It's vastly cheaper to have soil delivered in bulk than it is to buy individual bags, once your project is larger than a cubic yard or two.
Multiply the three dimensions: 6 × 6 × 3 = 108 cubic feet, which is exactly 4 cubic yards (108 ÷ 27 = 4).
Always 27. One cubic yard is a 3 ft × 3 ft × 3 ft cube, which equals 27 cubic feet — true for dirt, topsoil, sand, or any other bulk material.
It depends on the material: roughly 1.05 tons for topsoil, 1.1 tons for fill dirt, or 1.3 tons for sand, per cubic yard. Compost is lighter, at about 0.6 tons per cubic yard.
Final Thoughts
Calculating soil is not difficult if you follow the right method.
As explained clearly above:
"all you have to do to do this is to find the volume"
Using a dirt calculator makes your work easier and more accurate.
It helps you:
- Save money
- Avoid mistakes
- Complete your project smoothly
Daniel
Founder & Editor – TopSoilCalcOnline.com
Daniel is the founder and primary editor of TopSoilCalcOnline.com, a practical resource built to help homeowners, landscapers, and contractors accurately calculate topsoil, compost, and soil mix requirements. With hands-on experience in lawn preparation, raised beds, topdressing, and bulk soil planning, Daniel focuses on turning complex volume calculations into simple, reliable tools. Every calculator and guide on this site is designed to reduce material waste, prevent over-ordering, and help users plan landscaping projects with confidence and precision.