Garden Soil Calculator
Estimate garden soil volume, bag count, bulk yardage, weight, and optional cost from simple length, width, depth, and material inputs so you can plan raised beds, top-dressing, or new planting areas before ordering.
Garden Soil Inputs
Topsoil estimate
Soil Quantity Summary
Bulk volume
1.85 cu yd
50 cu ft for 100 sq ft at 6 in depth.
1.4 cu m if you are planning with metric supplier notes.
Coverage area
100 sq ft
9.29 sq m
Bag count
67 bags
0.75 cu ft bags
Estimated weight
3,704 lb
1,680 kg
Cost comparison
Bulk saves $279.44
$55.56 bulk vs $335.00 bags
Current Calculation
Area = length x width
10 ft x 10 ft = 100 sq ft
Volume (cu ft) = area (sq ft) x depth (ft)
100 sq ft x 0.5 ft = 50 cu ft
Cubic yards = cubic feet / 27
50 / 27 = 1.85 cu yd
Bags needed = cubic feet / bag size
50 / 0.75 = 67 bag(s)
Buying Breakdown
Topsoil is commonly used for:
Lawn top dressing, General garden beds, Leveling low spots, Blending with compost.
Bulk: $55.56 | Bags: $335.00
Use Scenarios
Filling a new raised bed
Use the page to turn bed length, width, and finished soil depth into cubic yards before you order a bulk delivery or stack bagged soil in the cart.
Refreshing an existing bed
A thinner top-up layer is easier to price if you measure only the bed surface and the added depth instead of guessing from last season's leftovers.
Comparing bags with bulk
Enter local yard and bag pricing when you want the calculator to show whether a small project is still easier to buy in bags or has grown into a delivery job.
Formula Explanation
1) Area
Area = length x width
Measure the interior planting footprint rather than the outside of the frame. For several identical beds, calculate one bed and multiply or combine the total area before ordering.
2) Convert depth into feet
Depth (ft) = inches / 12 or centimeters x 0.0328084
Bulk soil is commonly ordered in cubic yards, so the depth has to be expressed in feet before the volume can be converted into cubic feet and then cubic yards.
3) Volume
Volume (cu yd) = area (sq ft) x depth (ft) / 27
This is the core yardage formula. Metric inputs are converted internally, then the result is returned in cubic yards, cubic feet, and cubic meters so bag and bulk planning stay aligned.
4) Bags and cost
Bags = cubic feet / bag size, cost = quantity x unit price
Bag count uses the standard bag size assigned to the selected material. The cost comparison stays optional because local yard price, bag price, and delivery fees vary widely by supplier.
How to Read the Result
Cubic yards
Cubic yards are the bulk-order number most landscape suppliers want. If the result is 1.19 cubic yards, ordering 1.25 or 1.5 yards is often more practical than trying to hit the exact decimal.
Bag count
Bag count is useful for smaller projects and for transport planning. It depends on the bag size assumption attached to the selected material, so always compare it with the label in the store.
Weight and cost
Weight and cost are planning estimates rather than guaranteed delivery numbers. Moisture content, compaction, and supplier packaging can all move the real total away from the estimate.
Example Cases
Case 1: 4 x 8 ft raised bed
Inputs
- Area: 4 x 8 ft
- Depth: 12 in
- Material: Garden Soil
- Pricing: $45.00/cu yd and $6.00/bag
Computed Results
- Area: 32 sq ft
- Volume: 1.19 cu yd (32 cu ft)
- Bag count: 32 bags
- Weight: 2,133 lb
- Cost read: Bulk $53.33 vs bags $192.00; bulk saves $138.67
Interpretation
This is the classic single raised-bed build. It is large enough to feel expensive in bags, but still small enough that many gardeners compare both buying methods before ordering.
Decision Hint
Use the result to decide whether one small bulk load, a shared delivery, or a stack of store bags is the easier first-build option.
Case 2: Compost top-dressing
Inputs
- Area: 10 x 12 ft
- Depth: 3 in
- Material: Compost
- Pricing: $38.00/cu yd and $7.00/bag
Computed Results
- Area: 120 sq ft
- Volume: 1.11 cu yd (30 cu ft)
- Bag count: 30 bags
- Weight: 1,111 lb
- Cost read: Bulk $42.22 vs bags $210.00; bulk saves $167.78
Interpretation
A shallow layer changes the economics quickly. The area is fairly large, but the depth is thin enough that the project still lands under 1.2 cubic yards.
Decision Hint
This kind of top-up is a good moment to double-check whether you want a pure amendment layer or a blended topsoil-plus-compost mix instead.
Case 3: Metric courtyard bed
Inputs
- Area: 3 x 1.2 m
- Depth: 25 cm
- Material: Topsoil
- Pricing: $52.00/cu yd and $8.00/bag
Computed Results
- Area: 3.6 sq m
- Volume: 1.18 cu yd (31.8 cu ft)
- Bag count: 43 bags
- Weight: 1,068 kg
- Cost read: Bulk $61.21 vs bags $344.00; bulk saves $282.79
Interpretation
This metric example shows how a modest planting strip still turns into a meaningful bag count once the depth approaches a full root-zone fill rather than a thin refresh layer.
Decision Hint
When you work from metric plans, compare the cubic-meter read with local supplier notes, but keep the cubic-yard number handy if the seller still quotes in U.S. yardage.
Boundary Conditions
Sources & References
- Utah State University Extension - Raised Bed GardeningUsed for raised-bed filling guidance, including compost-enriched topsoil and the reminder that many beds are filled with a blended growing medium rather than one material alone.
- University of Alaska Fairbanks Cooperative Extension - Raised-Bed Gardening in AlaskaUsed for raised-bed dimension context and the practical reminder that a 12-inch bed is a common reference point for built-up rows and framed beds.
- Utah State University Extension - Using Compost in Utah GardensUsed for compost boundary notes, especially why compost works best as an amendment and why straight compost or high-compost potting mixes need more care than a simple full-bed fill assumption.
- Gill Nursery - Calculating Volumes of Soil For Your GardenKept as a supplementary practical reference for the length x width x depth workflow, the 27-cubic-feet-per-yard conversion, and bag-size translation examples commonly used when shopping for soil.