Topsoil Calculator
Estimate how many cubic yards, tons, or bags of topsoil you need for lawns, gardens, and landscaping projects. Supports both imperial and metric units, irregular areas, and waste allowance.
1. Choose area type
2. Enter dimensions
Common depths: 2–3 in for lawn topdressing, 4–8 in for new beds.
Optional. 5–15% is typical.
3. Soil density (for tons)
Typical screened topsoil: 1.0–1.3 tons per cubic yard (about 1200–1600 kg/m³).
4. Bag size (for bag count)
Common bag sizes: 0.5–1.0 ft³ (14–28 L). Check your supplier’s label.
Results
Enter your dimensions and click “Calculate topsoil” to see how much you need.
How this topsoil calculator works
This tool estimates how much topsoil you need based on the area you want to cover, the depth of the soil layer, and an optional allowance for settling and waste. It then converts the volume into cubic yards, cubic feet, cubic meters, approximate weight, and number of bags.
Volume formulas
1. Rectangle / square area
First convert all dimensions to feet, then:
\[ \text{Volume (ft³)} = \text{Length (ft)} \times \text{Width (ft)} \times \text{Depth (ft)} \]
2. Circular area
\[ \text{Area (ft²)} = \pi \times \text{Radius}^2 \]
\[ \text{Volume (ft³)} = \text{Area (ft²)} \times \text{Depth (ft)} \]
3. Custom area
If you already know the area \(A\) (in ft² or m²):
\[ \text{Volume} = A \times \text{Depth} \]
Unit conversions
- \(1 \text{ yard} = 3 \text{ feet}\)
- \(1 \text{ cubic yard} = 27 \text{ ft}^3\)
- \(1 \text{ meter} = 3.28084 \text{ ft}\)
- \(1 \text{ m}^3 \approx 35.3147 \text{ ft}^3\)
To convert from cubic feet to cubic yards:
\[ \text{Cubic yards} = \frac{\text{Cubic feet}}{27} \]
Weight estimation (tons and kilograms)
Topsoil weight depends on moisture, organic matter, and compaction. A common rule of thumb is:
- 1.0–1.3 tons per cubic yard for screened topsoil
- Dry, sandy soil is lighter; wet, clay-rich soil is heavier.
The calculator uses your chosen density to estimate weight:
If density is in tons per cubic yard:
\[ \text{Tons} = \text{Cubic yards} \times \text{Density (tons/yd³)} \]
If density is in kg/m³:
\[ \text{Kilograms} = \text{Cubic meters} \times \text{Density (kg/m³)} \]
Bag count estimation
Bagged topsoil is sold in various sizes, often labeled in cubic feet or liters. The calculator estimates the number of bags as:
Bag size in ft³:
\[ \text{Bags} = \frac{\text{Cubic feet}}{\text{Bag size (ft³)}} \]
Bag size in liters:
Use \(1 \text{ ft}^3 \approx 28.3168 \text{ L}\):
\[ \text{Bags} = \frac{\text{Cubic feet} \times 28.3168}{\text{Bag size (L)}} \]
Typical topsoil depths by project
| Project type | Recommended depth |
|---|---|
| Lawn topdressing / leveling low spots | 1–2 in (2.5–5 cm) |
| New lawn from seed or sod | 4–6 in (10–15 cm) |
| Vegetable beds & flower borders | 6–12 in (15–30 cm), depending on plant roots |
| Raised beds | 8–18 in (20–45 cm), often a mix of topsoil and compost |
Practical tips for ordering topsoil
- Check with your supplier for their typical density (tons per cubic yard) and bag sizes to improve accuracy.
- Order a bit extra (5–15%) to cover settling, compaction, and minor grade changes.
- Inspect quality: good topsoil should be relatively stone-free, not overly compacted, and free of obvious contaminants.
- Mix with compost for nutrient-poor soils, especially in vegetable gardens and flower beds.
Topsoil Calculator FAQ
How do I calculate how many yards of topsoil I need?
Measure the length and width of the area in feet, decide on a depth in inches, then convert depth to feet (divide by 12). Multiply length × width × depth (ft) to get cubic feet, then divide by 27 to get cubic yards. The calculator automates all of this and supports metric units as well.
Is it better to buy topsoil in bulk or in bags?
For small projects (a few wheelbarrows), bags can be convenient. For anything over about 1–2 cubic yards, bulk delivery is usually cheaper per unit volume. Use the calculator to compare the cost per cubic yard of bags versus bulk.
How many bags of topsoil equal 1 cubic yard?
If each bag is 0.75 ft³, then 1 cubic yard (27 ft³) is about 36 bags. If each bag is 0.5 ft³, you need about 54 bags. The calculator lets you enter your exact bag size and will compute the bag count for you.
Does wet topsoil weigh more?
Yes. Moisture significantly increases the weight of topsoil. That’s why the calculator allows you to adjust density. If your supplier gives you a typical tons-per-yard figure for their product, use that for the most accurate weight estimate.