Square Feet to Cubic Yards Calculator

Convert any dimensions -- in feet or inches -- to cubic yards. Works for concrete, gravel, mulch, topsoil, and any other material.

Every concrete project depends on hitting the right compressive strength. The difference between 2,500 PSI and 3,500 PSI is the difference between a slab that lasts decades and one that cracks within years.

ASTM C94/C94M sets how ready-mixed concrete is batched, measured and delivered, but it does not fix one default strength for every pour. Quality requirements are either those stated in the specification or those ordered by the buyer, and where the two differ, it is the purchaser's own specification that governs.

-- ASTM International, C94/C94M Standard Specification for Ready-Mixed Concrete

That one line is why the number on your delivery ticket matters more than any blanket figure you read online. C94/C94M is an end-result specification. It tells the plant what to prove, not what to pour. You name the strength when you order, and for most residential work that lands between 3,000 and 4,000 psi at 28 days. A plant will batch weaker if nobody says otherwise.

Source: ASTM C94/C94M, explained in NRMCA Concrete in Practice -- nrmca.org

The National Ready Mixed Concrete Association publishes Concrete in Practice, a free series of one-page technical sheets written in a plain what, why and how format for contractors and owners.

-- National Ready Mixed Concrete Association, Concrete in Practice series

Those sheets are the fastest sanity check we know of when a contractor tells you something that sounds off. Short, free, and written by the people who actually batch the material.

Source: NRMCA Concrete in Practice -- nrmca.org

Square Feet to Cubic Yards Guide

Cubic Yard Results

Cubic Yards
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yd³
Cubic Feet
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ft³
Est. Cost
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material estimate
Cubic Meters
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Cubic Inches
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in³
Gallons
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US gallons
Volume Summary
Total Volume (cubic yards)
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Concrete bags equivalent (80 lb)
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Estimated material cost
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Common Material Densities
MaterialWeight/yd³Tons/yd³Typical Price
Concrete (3000 PSI)4,050 lbs2.03 tons$125-$195/yd³
Gravel (crushed stone)2,800 lbs1.40 tons$50-$90/yd³
Topsoil2,100 lbs1.05 tons$30-$65/yd³
Sand2,700 lbs1.35 tons$25-$60/yd³
Mulch (shredded bark)400-800 lbs0.3 tons$25-$50/yd³
Pea Gravel2,500 lbs1.25 tons$55-$100/yd³
Understanding Cubic Yards: A Practical Guide
How volume calculations work for concrete, gravel, topsoil, and more
Why Everything Is Measured in Cubic Yards

The construction industry standardized on cubic yards because it's a practical unit for truck delivery: a standard ready-mix drum truck holds 8-10 cubic yards. A dump truck of gravel or topsoil holds 10-14 cubic yards. When you call a supplier, you order by the yard -- so knowing how to convert your project dimensions directly to yards is the one skill that saves you from ordering too much or running short.

The formula is always the same: cubic yards = (L × W × D in feet) ÷ 27. The "27" comes from the fact that one cubic yard contains exactly 27 cubic feet (3 ft × 3 ft × 3 ft). Everything else -- bag counts, cost estimates, weight calculations -- flows from that one number.

27
ft³ per yd³
3 ft × 3 ft × 3 ft -- the fundamental conversion
4,050
lbs of concrete
Weight of one cubic yard of 3000 PSI concrete
202
gallons per yd³
US gallons in one cubic yard of liquid volume
Inches vs. Feet: The Most Common Calculation Mistake

The single most common error in DIY material calculations is mixing inches and feet. A 4-inch slab depth is 0.333 feet, not 4 feet. Entering 4 instead of 0.333 gives you a result 12× too large -- you'd order enough concrete for a 4-foot thick slab. Always convert depth from inches to feet by dividing by 12 before multiplying. Our calculator handles this conversion automatically when you select the Inches input mode.

Square Feet Conversion Reference

Common conversions between cubic yards, cubic feet, and bags
1 Cubic Yard =
  • 27 cubic feet
  • ~45 bags of 80lb concrete
  • ~60 bags of 60lb concrete
  • ~1.4 tons of gravel (dry)
  • 27 bags of 2 cu ft mulch
Rule of 81 (for concrete)

For a 4-inch slab, divide total square footage by 81 to get cubic yards. Example: 200 sq ft ÷ 81 = 2.47 yards. This works because 1 cu yd covers exactly 81 sq ft at 4-inch depth.

Square Feet to Cubic Yards -- The Formula Explained

Why you need to know this conversion and exactly how to do it

Square feet measures area (a flat surface). Cubic yards measures volume (area plus depth). Ready-mix concrete, gravel, topsoil, mulch, and sand are all sold by the cubic yard -- but you measure your project in square feet. This conversion bridges those two units.

The formula: (Length × Width × Depth in inches) ÷ 324 = Cubic Yards. The number 324 comes from converting 27 cubic feet per yard × 12 inches per foot = 324.

Area (sq ft) 2" depth 4" depth 6" depth 12" depth
100 sq ft0.62 yds1.23 yds1.85 yds3.70 yds
200 sq ft1.23 yds2.47 yds3.70 yds7.41 yds
300 sq ft1.85 yds3.70 yds5.56 yds11.11 yds
500 sq ft3.09 yds6.17 yds9.26 yds18.52 yds
1,000 sq ft6.17 yds12.35 yds18.52 yds37.04 yds
2,000 sq ft12.35 yds24.69 yds37.04 yds74.07 yds

What One Cubic Yard Covers

At common depths -- so you can work backwards from a delivery quantity
Concrete at 4"
81 sq ft
Standard slab, patio, driveway
Gravel at 4"
81 sq ft
Driveway base, drainage layer
Mulch at 3"
108 sq ft
Garden beds, tree rings

The easiest way to remember the concrete conversion: divide your square footage by 81 to get cubic yards for a 4-inch slab. This works because one cubic yard covers exactly 81 square feet at 4 inches deep. For other depths, multiply 81 by (4 ÷ your depth in inches).

Material Weights Per Cubic Yard

Important for estimating delivery truck loads and equipment requirements
Material Lbs per Cu Yd Tons per Cu Yd Notes
Ready-mix concrete3,7001.85Full truck = ~9 yds = 33,300 lbs
Gravel (dry)2,8001.40Washed stone, pea gravel
Sand2,7001.35Dry -- wet sand is heavier
Topsoil2,0001.00Dry loam estimate
Mulch (wood chips)400-6000.20-0.30Much lighter -- pickup truck friendly

Cubic Yards FAQ

Common questions about calculating cubic yards for any project

How do I calculate cubic yards?+

Multiply length × width × depth (all in feet) then divide by 27. The number 27 comes from the fact that one cubic yard contains 27 cubic feet (3 × 3 × 3).

How many cubic yards are in a ton?+

It depends on material density. Concrete: about 0.5 yd³ per ton. Gravel: about 0.75 yd³ per ton. Topsoil: about 0.95 yd³ per ton. Mulch: about 3 yd³ per ton.

How many cubic yards fit in a pickup truck?+

A standard 6-foot pickup truck bed safely holds about 1-1.5 cubic yards of dense material. Check your truck's payload rating before loading heavy materials.

How do I convert inches to cubic yards?+

Divide each inch measurement by 12 to convert to feet, then use L × W × D ÷ 27. Our calculator also accepts inch inputs directly and converts automatically.

What does one cubic yard look like?+

One cubic yard is a cube measuring exactly 3 feet on each side -- roughly the size of a large front-loading washing machine or a standard bathtub filled to the brim.

How many wheelbarrow loads are in a cubic yard?+

A standard contractor wheelbarrow holds 3-4 cubic feet. Since 1 cubic yard = 27 cubic feet, you need approximately 7-9 wheelbarrow loads per cubic yard.

What is the difference between cubic yards and square yards?+

Square yards measure area (length × width, no depth). Cubic yards measure volume (length × width × depth). You need cubic yards whenever calculating three-dimensional material volume.

Last updated . Formulas reviewed by Joe R., Masonry Specialist, and Elena S., Civil Engineer (PE). Spotted a number that looks wrong? Report a Data Error and we will re-verify it against the source.