Soil & Topsoil Calculator — Cubic Yards
Calculate how much topsoil, garden soil, fill dirt, or compost you need. Use the raised bed presets or enter custom dimensions to get volume, bag count, weight, and cost estimates.
Soil & Topsoil Calculator
Soil Types and Uses
| Type | lb/cu ft | kg/m³ | Best For |
|---|---|---|---|
| Topsoil | 75 | 1,200 | Lawns, general landscaping |
| Garden soil (amended) | 75 | 1,200 | Flower beds, vegetables |
| Fill dirt | 110 | 1,762 | Grading, filling holes |
| Compost | 40 | 641 | Soil amendment, mulch |
| Potting mix | 30 | 481 | Containers, indoor plants |
How Deep Should Soil Be?
- New lawn: 4–6 in (10–15 cm) of topsoil.
- Flower beds: 8–12 in (20–30 cm).
- Raised beds: 12–18 in (30–45 cm); minimum 6″ (15 cm).
- Vegetable garden: 12+ in (30+ cm).
- Trees: 18–24 in (45–60 cm) around root ball.
How to Calculate Soil for Your Project
- Measure the area in feet: length and width. For raised beds, measure the inside dimensions.
- Determine depth: 4–6″ for lawns, 6–12″ for garden beds, 12″ for raised beds.
- Calculate volume: L × W × (depth ÷ 12) = cubic feet. Divide by 27 for cubic yards.
- Convert to bags: Divide cubic feet by 2 (standard bag) and round up.
Imperial example: A 4 × 8 ft raised bed, 12″ deep: 4 × 8 × 1 = 32 cu ft ÷ 27 = 1.19 cubic yards = 16 US bags (2 cu ft each).
Metric example: A 1.2 m × 2.4 m raised bed, 30 cm deep: 1.2 × 2.4 × 0.30 = 0.86 m³ (860 liters) = 18 bags (50 L each).
Raised Bed Soil Mix Recipes
Classic Mix
60% topsoil + 30% compost + 10% perlite/vermiculite. Good all-purpose mix for most vegetables and flowers. Affordable and easy to source in bulk.
Mel’s Mix (Square Foot Gardening)
1/3 compost + 1/3 peat moss + 1/3 vermiculite. Lightweight, excellent drainage. Ideal for intensive square-foot gardening. More expensive but very productive.
Budget Mix
50% topsoil + 50% compost. Simplest and cheapest option. Works well for most gardens. Add perlite if drainage is a concern in your area.
Frequently Asked Questions
How much soil do I need for a 4×8 raised bed?
At 12 inches deep: 4 × 8 × 1 = 32 cu ft = 1.19 cu yd ≈ 16 bags (2 cu ft each). Use a mix of 60% topsoil + 30% compost + 10% perlite/vermiculite for best results.
What is the difference between topsoil and garden soil?
Topsoil is screened natural soil — good for lawns, grading, and filling. Garden soil is topsoil + compost and organic amendments — better drainage and nutrients. Garden soil costs more but is better for planting.
How much does a yard of topsoil weigh?
About 2,000 lbs (1 ton) when dry. Wet topsoil can weigh 2,500–3,000+ lbs per cubic yard. Garden soil is slightly heavier at about 2,160 lbs/cu yd.
Can I reuse old raised bed soil?
Yes — refresh with 2–3 inches of compost each season. Replace completely every 5–6 years when the soil becomes compacted and nutrient-depleted.
Related Calculators
- Mulch Calculator — need mulch on top?
- Cubic Yards Calculator — building the raised bed frame? Calculate volume
- Gravel Calculator — for drainage and pathways
- Sand Calculator — sand to amend or level the soil
- Area Unit Converter — convert between square feet, square meters, acres, hectares
- All Construction Calculators
Soil densities are dry averages and vary with moisture content. Prices are 2025 US national averages and will vary by region and supplier.
