LandscapingRaised Bed Soil Calculator

Raised Bed Soil Calculator

How much soil for a raised bed? Calculate cubic feet, bags, and bulk delivery for any raised garden bed. Includes soil mix ratios and cost estimates.

Bed Details

Bed Shape

Length (ft)

Width (ft)

Bed Depth (inches)

Soil Mix

Ready to calculate

Enter your bed details for a soil estimate

Last updated March 2026 by our expert review team

Cost per Cubic Yard by Soil Mix

$/cu yd
Topsoil Only$25 - $45 /cu yd
Garden Mix (60/40)$35 - $55 /cu yd
Raised Bed Mix (1/3/1/3/1/3)$40 - $65 /cu yd
Compost-Heavy (30/70)$50 - $80 /cu yd

Prices are for bulk delivery. Bagged soil costs 40 to 60% more per cubic yard equivalent.

Expert Contributors

RW
Creator
Ruth Wairimu
Landscape Architect
H
Expert Review
Hawkin
Certified Cost & Estimating Professional

Pro Tips

1

The classic raised bed mix is 1/3 topsoil, 1/3 compost, 1/3 peat moss or vermiculite. This creates perfect drainage and nutrient balance for vegetables.

2

For beds deeper than 12 inches, fill the bottom half with cheaper material first. Use our fill dirt calculator to estimate the base layer.

3

After planting, top your beds with 2 to 3 inches of mulch to retain moisture and suppress weeds. Our mulch calculator can help with that estimate.

4

Bulk delivery is 40 to 60% cheaper than bagged soil for beds over 1 cubic yard. Most suppliers deliver minimum 1 to 2 cubic yards.

5

Soil settles 10 to 15% in the first season. Fill beds 2 inches above the rim and top off with compost each spring.

6

Line the bottom of wooden raised beds with landscape fabric to prevent soil from washing out through gaps. Don't use plastic; it blocks drainage.

How the Calculator Works

1

Choose your bed shape (rectangular, circular, or L-shaped) and enter the dimensions.

2

Set the bed depth in inches (or cm for metric) and pick your soil mix type.

3

Get cubic feet, cubic yards, bag counts, cost estimates, and a breakdown of each soil component.

Formulas

Rectangular: Length x Width x (Depth / 12)

Circular: Pi x (Diameter / 2)^2 x (Depth / 12)

Cubic Yards = Cubic Feet / 27

2-cu-ft Bags = Cubic Feet / 2 (rounded up)

Quick Reference

1 cubic yard
27 cu ft
2-cu-ft bag
$5 to $8 retail
Bulk delivery min
1 to 2 cu yd
Settling
10 to 15% first year
Min depth (veggies)
12 inches

Common Questions

How much soil for a 4x8 raised bed?

About 32 cubic feet (1.2 cu yd) at 12 inches deep. That's 16 bags of 2-cu-ft soil or about 1 cubic yard bulk delivery.

What is the best soil mix for raised beds?

1/3 topsoil, 1/3 compost, 1/3 peat moss or vermiculite. This provides nutrients, drainage, and water retention for vegetables and flowers.

How deep should a raised bed be?

12 inches minimum for most vegetables. 6 inches for lettuce and herbs. 18 to 24 inches for root vegetables like carrots and potatoes.

Bulk soil vs bagged?

Bulk is $25 to $80 per cubic yard delivered. Bagged costs $5 to $8 per 2 cu ft bag ($67 to $108 per cu yd equivalent). Bulk saves 40 to 60% for larger beds.

How much does raised bed soil cost?

$30 to $100 per cubic yard for bulk delivery depending on mix quality. A standard 4x8x1 ft bed costs $35 to $100 for soil.

Should I put anything under the soil?

Cardboard on the bottom suppresses weeds. Landscape fabric prevents soil washout. Don't use plastic sheeting as it blocks drainage.

How often should I add soil to raised beds?

Add 2 to 3 inches of compost each spring. Soil settles and decomposes over the season, losing 10 to 15% of its volume.

Can I fill the bottom with something cheaper?

For beds deeper than 12 inches, fill the bottom half with wood chips, straw, or logs (hugelkultur method). Top with 12 inches of quality soil mix.

Real-World Raised Bed Examples

Small Herb Bed

4x2, 6" deep
Result: 4 cu ft, 2 bags

A compact herb bed. Just 2 bags of 2-cu-ft soil from the store. Budget $10 to $16 for bagged soil.

Standard Veggie Bed

4x8, 12" deep
Result: 32 cu ft, 16 bags

The most popular raised bed size. About 1.2 cubic yards. Budget $48 to $77 for bulk delivery or $80 to $128 bagged.

Large Garden Bed

4x12, 12" deep
Result: 48 cu ft, 24 bags

A full-size garden bed at 1.8 cubic yards. Bulk delivery saves significantly at this size. Budget $71 to $115 bulk.

Circular Flower Bed

6 ft diameter, 12" deep
Result: 28 cu ft, 14 bags

A round flower bed with about 28 sq ft of area. Budget $42 to $67 for bulk or $70 to $112 bagged.

Raised Bed Soil Mistakes That Cost You Money

Using only topsoil

Pure topsoil is too dense for raised beds. It compacts over time and drains poorly. Always mix with compost and amendments for proper root growth.

Not accounting for settling

Soil settles 10 to 15% in the first season. Fill beds 2 inches above the rim so you don't end up with a half-empty bed by summer.

Filling deep beds entirely with premium mix

For beds deeper than 12 inches, use cheaper fill for the bottom half. Wood chips, straw, or logs work great. Save the quality soil mix for the top 12 inches where roots grow.

Forgetting drainage

Never line the bottom with plastic sheeting. It traps water and drowns roots. Use landscape fabric if you need a barrier, and make sure the bed has contact with the ground.

Under-ordering bags

Always round up when buying bagged soil. Leftover soil goes in garden borders, pots, or topdressing the lawn. Running short mid-project means another trip to the store.

Important Disclaimer

These estimates are for planning purposes only. Actual costs vary by location, material availability, and project complexity. Always get at least 3 local quotes. This calculator does not replace professional advice.