Square Feet to Cubic Feet Calculator
Convert any square footage to cubic feet, cubic yards, tons, and bag counts by adding a depth. Perfect for ordering mulch, gravel, topsoil, sand and concrete with contractor-grade accuracy.
Quick presets
Project Details
Cross-section visual
Vehicle loads required
- Sedan trunk4 loads
- SUV / mid-size hatch2 loads
- Compact pickup (4 ft bed, level)2 loads
- Full-size pickup (8 ft bed, level)1 load
- Single-axle dump truck1 load
Volumes are level-fill estimates. Verify your vehicle payload rating before loading heavy aggregate or wet topsoil.
Converting Square Feet to Cubic Feet: The Complete Guide
Square feet measure area; cubic feet measure volume. They are not interchangeable units but they are connected by a single missing piece of information: depth. Multiply your area in square feet by a depth expressed in feet and you have cubic feet. That single multiplication is the most common bulk-material question in landscaping, hardscaping, gardening, and small-scale construction. Mulch, gravel, topsoil, sand, and concrete are all sold by volume yet measured on the ground by area, which means every project starts with a sq ft to cu ft conversion.
The formula is simple but the units trip people up. Most landscape layers are inches thick — a 3-inch mulch ring or a 4-inch gravel base — so you have to convert inches to feet first. Divide inches by 12 to get the equivalent decimal feet. For example, 100 sq ft at 3 inches deep equals 100 × (3 / 12) = 100 × 0.25 = 25 cubic feet. Our calculator does that conversion automatically when you toggle the depth unit between inches and feet, so you can think in the units that match your tape measure.
Once you have cubic feet, the rest of the math is just unit conversion: divide by 27 to get cubic yards (how bulk suppliers price material), multiply by 0.0283 to get cubic meters, multiply by 7.48 to get US gallons, or multiply by the density of your material to get pounds and tons. Always add a waste factor — typically 10% for mulch, topsoil, and decorative gravel; 15-20% for compacted aggregate base; and 5-10% for ready-mix concrete — because materials settle, compact, and spread unevenly. The waste percentage is the single biggest reason DIY orders come up short.
Material density reference
Densities below are typical mid-range values; check your supplier for exact specifications.
| Material | Density (lb/cu ft) | Per cu yd (lb) | Notes |
|---|---|---|---|
| Mulch (shredded bark) | 25-50 (avg 40) | ~1,080 | 3-inch depth typical for beds |
| Topsoil | 75-100 (avg 90) | ~2,430 | Heavier when wet |
| Sand (dry, loose) | 100 | ~2,700 | Add ~10% if wet |
| Gravel / crushed stone | 95-110 | ~2,800-3,000 | Compact 15-20% extra |
| Pea gravel / river rock | 100 | ~2,700 | Decorative, 2-3 inch |
| Concrete (ready-mix) | 150 | ~4,050 | 4-6 in slab thickness |
| Water (reference) | 62.4 | ~1,685 | Baseline density |
5 steps: square feet to cubic feet, end to end
- 1Measure each zone
Use a tape measure to record the length and width of every bed, pad, or fill area in feet. Add zones in the calculator and the total square footage updates live as you type.
- 2Pick the right depth
Set the depth in inches for thin landscape layers (mulch, topsoil, decorative gravel) or feet for thicker fills and slabs. Industry-standard depths: 3 in mulch, 2-3 in decorative gravel, 4 in paver base, 4 in residential slab, 6 in driveway slab.
- 3Choose your material
Selecting a material loads the correct density (for weight) and bag size (for retail counts). Hit the custom-density checkbox if your supplier publishes a different value on the spec sheet.
- 4Add a waste factor
A 10% waste factor is the right starting point for mulch, gravel, and topsoil. Up it to 15-20% for compacted base and down to 5-10% for ready-mix concrete.
- 5Order the right way
Use the cubic-yard number to order bulk delivery, the bag count to shop retail, and the truck-load number to plan how many trips you need. The export button generates a printable estimate.
Popular use cases
Mulching flower beds
Mulch beds at 3 inches; double-shred bark, hardwood, or dyed mulch all use about the same volume. Calculate every bed once and combine for a single delivery.
Open the dedicated Mulch Calculator →Paver patio base
A 12 × 16 ft patio at 4 inches needs about 64 cu ft (2.4 cu yd) of crushed stone base — order 15-20% more to compact.
Open the dedicated Gravel Calculator →Concrete slab pour
Pad, shed floor, or driveway: enter the slab footprint, set depth to 4-6 in, and choose Concrete to get a clean cubic-yard number for the ready-mix order.
See our general Cubic Feet Volume Calculator →Topsoil & raised beds
Calculate fill for raised vegetable beds or lawn-level dressing. Six inches of topsoil over 100 sq ft is 50 cu ft — about 1.85 cu yd.
Convert to Cubic Yards (sqft to cuyd) →Pro tips from landscapers and contractors
- Compact aggregate base in 2-inch lifts with a plate compactor. Expecting compaction up front is the difference between a flat patio and a wavy one two years later.
- Bulk materials settle 5-15% within the first season — order to your final compacted depth, not your loose-fill depth, and the math works out.
- On a first-time project, order a fresh-cu-yd extra. Returning to the bulk yard costs an afternoon; running short costs the same plus the contractor standing around.
- Always round bag counts up. A short bag means a second store trip; a spare bag means a head start on next season.
- Heap mulch piles after delivery to keep them dry. Wet mulch can gain 10-20% in weight, throwing off your truck payload count.
- Concrete is sold in 1/4 cu yd increments by most ready-mix plants. Round your order up to the next quarter yard rather than splitting hairs in cubic feet.
Trusted by landscapers and DIYers
“I plug in the bed dimensions, depth, and material right in front of the customer at the consultation. They see the cubic yards, ton weight, and bag count instantly. It has cut my quoting time in half and the cost numbers always match what the bulk yard charges.”
“I needed to figure out how many bags of mulch for two big flower beds and the math was making my head spin. This calculator added both areas, applied a waste factor, and told me to grab 18 bags. Got back from the garden centre with two to spare which is exactly what I wanted.”
“I use this every day for slab takeoffs before I open my big estimating program. It handles depth in inches, waste, and the truck-load output is great for telling guys whether we need one short load or two. The dark mode is easy on the eyes during long days.”
“We point customers at this calculator on the in-store iPads. It speaks plain language, has the right bag sizes, and customers leave with the right amount of mulch or topsoil the first time. Returns are down because the orders are right the first time.”
Love using our calculator?
Similar Calculators
More tools in the same category
Board and Batten Layout Calculator
Calculate board and batten spacing for perfect layouts
Feet and Inches Calculator
Add, subtract, and convert feet and inches measurements
Scale Calculator
Convert between different measurement scales for plans
Square Footage Calculator
Calculate room and area square footage accurately
Lumber Weight Calculator
Calculate lumber weight from species, dimensions and quantity. 17+ wood species, kiln-dried/green/pressure-treated moisture.
Cabinet Door Size Calculator
Calculate cabinet door dimensions for full overlay, partial overlay, or inset construction. Auto hinge count.
Often Used Together
Complementary tools for complete analysis
From Other Categories
Expand your calculations
Geometry and area calculations for building
Measurement unit conversions
Project cost and budget calculations
You Might Also Like
Based on similar functionality
Related Articles
Dive deeper with our expert guides and tutorials related to Square Feet to Cubic Feet Calculator