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Concrete Yardage Calculator

Calculate exactly how much concrete you need for any slab -- patios, driveways, garage floors, and more. Get cubic yards, bag counts, and a complete shopping list.

Concrete thickness standards are set by engineering organizations with decades of field research behind them. Getting the depth right on your first pour prevents costly cracking and premature failure.

"Non-reinforced pavement four inches thick is standard for passenger car driveways. For heavier vehicles, a thickness of five inches is recommended."

-- American Cement Association (cement.org) -- Concrete Driveways Guide

Source: American Cement Association -- cement.org

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Calculate cubic yards of concrete for slabs, footings, walls, and any custom dimensions -- with delivery cost guidance.

Concrete Yard Quick Reference Table

Slab Size 4-inch Slab 6-inch Slab Order As
10×10 ft1.36 cu yd2.04 cu yd1.5 or 2.25 yd (short-load)
10×20 ft2.71 cu yd4.07 cu yd3 or 4.25 yd
12×20 ft (driveway)3.26 cu yd4.89 cu yd3.5 or 5 yd
20×20 ft (garage)5.43 cu yd8.15 cu yd6 or 8.5 yd
20×40 ft (RV pad)10.86 cu yd16.30 cu yd11 or 16.5 yd (2 trucks)

All values include the 10% wastage buffer. Most ready-mix plants order in 0.25-yard increments, so you cannot order exactly 1.36 yards -- round up to 1.5. The extra 0.14 yard costs about $22 but eliminates the risk of running out mid-pour.

Ready-Mix Truck Capacity and Short-Load Fees

Standard ready-mix trucks carry 8-10 cubic yards. Smaller trucks (called "mini-mix" or "mud-mixer" trucks) carry 1-4 yards but cost more per yard delivered. Understanding the truck pricing tiers:

  • Under 1 yard: Plants typically refuse. Use bags or rent a mini-mixer truck.
  • 1-2 yards: $200-275 per yard (includes short-load surcharge). Mini-mix or "trailer-haul" services available in some areas.
  • 3-5 yards: $140-180 per yard. Standard pricing tier. Short-load fee of $50-100 usually waived above 3 yards.
  • 6-10 yards: $130-165 per yard. Sweet spot for residential driveways.
  • 10+ yards: May require 2 trucks. Pricing similar to 6-10 yard range, but coordinate truck timing -- second truck arrives 15-30 minutes after first.

Additional fees that show up on the invoice: Saturday delivery (+$50-100), after 4pm delivery (+$50), wash-out fee ($25-50 if you do not have a designated wash-out spot), and pump truck if needed ($250-500 for hard-to-reach pours).

Calculating Yardage for Non-Rectangular Shapes

For irregular shapes, break the pour area into rectangles and add the volumes. For circular columns or sonotubes: Volume = π × radius² × depth, then divide by 27 to convert to cubic yards.

Examples for common circular pours (cu yd):

  • 10-inch sonotube × 4 ft deep: 0.08 cu yd (need 0.1 yd order)
  • 12-inch sonotube × 4 ft deep: 0.12 cu yd
  • 12-inch sonotube × 8 ft deep: 0.23 cu yd
  • 8-foot diameter circle, 4 inch deep: 0.62 cu yd
  • 12-foot diameter circle, 4 inch deep: 1.40 cu yd

For multiple deck footings or sonotubes, calculate one and multiply. For complex L-shapes or pour designs with varying depths, break into rectangles, calculate each, and sum.

Concrete Yardage FAQ

How do I calculate concrete yardage?
Multiply length × width × thickness (all in feet -- convert inches by dividing by 12). The result is cubic feet. Divide cubic feet by 27 to get cubic yards. Always add 10% for wastage. For a 10×20 patio at 4 inches thick: 10 × 20 × 0.333 = 66.67 cu ft ÷ 27 = 2.47 cu yd × 1.10 = 2.72 cu yd to order.
What is the minimum order for ready-mix concrete?
Most plants require a 3 cubic yard minimum. Under 3 yards triggers a "short-load fee" of $50-150. Some plants will deliver as little as 1 yard with a higher short-load charge ($150-250 added). Below 1 yard, you are generally better off using bagged concrete from Home Depot or Lowe's.
How much does 1 yard of concrete cost in 2026?
Standard 3000 PSI ready-mix concrete runs $140-$180 per cubic yard in most US metro areas. High-strength 4000 PSI adds 15-20%. Add fees: short-load ($50-150 under 3 yards), fuel surcharge ($10-30), Saturday delivery ($50-100), pump truck ($250-500 if needed). Total installed cost for a 3-yard order typically runs $500-700.
How many bags of concrete equal 1 cubic yard?
You need approximately 45 bags of 80-lb concrete, 60 bags of 60-lb, or 90 bags of 40-lb to equal 1 cubic yard. With the 10% wastage buffer included, the math is: 1 cubic yard = 1 cu yd × 1.10 × yield per bag. An 80-lb bag yields 0.60 cu ft, so 27 ÷ 0.60 = 45 bags pre-waste; 45 × 1.10 = 50 bags with buffer included.
Should I order an extra yard of concrete just in case?
For pours under 5 yards: order 10% over your raw math (the wastage buffer this calculator already builds in). For pours over 5 yards: order exact rounded math -- the buffer is already substantial in absolute volume. Returning unused concrete costs $50-100 in disposal fees at most plants. Running short is much worse -- a cold joint where you ran out and re-poured later creates a permanent structural weak point.
Related Calculators
→ Yard Calculator→ Cubic Yards Calculator→ Cost Calculator→ Slab Calculator