How many cubic yards of concrete do I need for a 10x10 slab?

A 10×10 foot slab at 4 inches thick needs 1.23 cubic yards of concrete (33.3 cubic feet ÷ 27). With 10% waste factor, order about 1.5 yards or use 62 bags of 80lb mix.

How many bags of concrete equal 1 cubic yard?

One cubic yard equals 45 bags of 80lb concrete or 60 bags of 60lb concrete. One cubic yard is 27 cubic feet total.

When should I order a ready-mix truck instead of buying bags?

Order a truck when your project exceeds 1 cubic yard (45 bags). Ready-mix delivery at $125–$175 per yard is cheaper and faster than hand-mixing 45+ bags, and produces a stronger monolithic pour without cold joints.

How much does a cubic yard of concrete cost from a truck?

Ready-mix concrete costs $125–$175 per cubic yard for standard delivery in 2026. Add $50–$100 for short-load fees (under 4 yards), plus $150–$350 for a pump truck if needed for hard-to-reach areas.

How Many Yards of Concrete Do I Need? Complete Yard Calculator Guide

Quick formula: Cubic Yards = Length (ft) × Width (ft) × Thickness (in) ÷ 12 ÷ 27. One cubic yard = 27 cubic feet = 45 bags of 80lb concrete. Add 10% for waste. Ready-mix delivery ($125–$175/yd) beats bags for any project over 1 cubic yard.

Understanding Cubic Yards of Concrete

A cubic yard is the standard ordering unit for ready-mix concrete delivery. One cubic yard equals 27 cubic feet — picture a cube that’s 3 feet on each side. That’s also 45 bags of 80lb concrete or 60 bags of 60lb concrete. When you call a concrete supplier to order a truck, they’ll ask “how many yards?” — this guide helps you calculate that number accurately.

The Concrete Calculator Yard Formula

Converting your project dimensions to cubic yards follows three steps:

Calculate volume in cubic feet: Length (ft) × Width (ft) × Thickness or Depth (ft)
Convert to cubic yards: Divide cubic feet by 27
Add waste factor: Multiply by 1.05 to 1.15 (5–15% extra)

Quick Formula

Cubic Yards = (L × W × T÷12) ÷ 27 × (1 + waste%)

Where L and W are in feet, T is thickness in inches.

How Many Yards for Common Projects

Project	Dimensions	Cubic Yards
10×10 patio (4”)	100 sq ft	1.23 yd³
10×20 driveway (5”)	200 sq ft	3.09 yd³
20×20 garage (5”)	400 sq ft	6.17 yd³
24×24 garage (5”)	576 sq ft	8.89 yd³
30×40 shop (5”)	1,200 sq ft	18.52 yd³
4×50 sidewalk (4”)	200 sq ft	2.47 yd³
20 fence posts (10”×30”)	—	1.01 yd³
4 deck footings (12”×42”)	—	0.41 yd³

When to Order Ready-Mix vs Buy Bags

The crossover point where ready-mix truck delivery becomes more economical than bags is approximately 1 cubic yard (27 cubic feet). Here’s the comparison:

Cost per Cubic Yard

Method	Cost per Yard	Labor Time	Notes
60lb bags	$800–$900	6–8 hours mixing	60 bags per yard
80lb bags	$630–$750	4–6 hours mixing	45 bags per yard
Ready-mix truck	$125–$175	10 min delivery	Minimum 1 yd usually
Short-load truck	$175–$275	10 min delivery	Under-minimum fee

The math is clear: even with a short-load fee, truck delivery saves you hundreds of dollars in labor time for anything over 1 cubic yard.

Ordering Ready-Mix Concrete: What to Know

Minimum Order

Most ready-mix plants have a minimum order of 1 cubic yard. Below that, you’ll pay a “short-load fee” of $50–$100 on top of the per-yard price.

Ordering Extra

Always order 5–10% more than your calculation shows. Unlike bags where you can return extras, ready-mix that arrives is yours. But running short mid-pour is far worse than having a small amount left over. Pour leftover concrete into simple forms for stepping stones or post bases.

Delivery Logistics

Truck needs access within 200 feet of the pour site (further requires a pump truck at $150–$300)
Typical truck holds 8–10 cubic yards
Pour rate is about 1 yard per minute from the chute
Concrete starts setting in 60–90 minutes after mixing
Weekday delivery is cheaper than Saturday; Sunday is often unavailable

Ready-Mix Specifications

When ordering, specify:

Volume: Total cubic yards
PSI strength: 3,000 PSI for slabs/patios, 4,000 PSI for driveways, 4,500 PSI for garage floors
Slump: 4–5 inches for slabs (how fluid the mix is)
Fiber or rebar: Let the supplier know if you want fiber mesh added

Concrete Calculator in Yards: Worked Examples

Example 1: Driveway Slab

A 12×30 foot driveway at 5 inches thick:

Volume = 12 × 30 × (5÷12) = 150 cu ft
In yards = 150 ÷ 27 = 5.56 cubic yards
With 10% waste = 6.11 cubic yards
Order: 6.5 yards (round up to nearest half-yard)

Example 2: Patio + Sidewalk Combined Pour

Patio: 14×16 ft at 4” = 74.7 cu ft = 2.77 yd³
Sidewalk: 4×20 ft at 4” = 26.7 cu ft = 0.99 yd³
Combined = 3.76 yd³
With 10% waste = 4.13 cubic yards
Order: 4.5 yards

Example 3: Deck Footings (8 piers)

12” diameter sonotubes, 48” deep
Each pier = π × (0.5)² × 4 = 3.14 cu ft
8 piers = 25.1 cu ft = 0.93 cubic yards
With waste = 1.02 yards
This is right at the minimum — bags might be more practical unless pouring with the footings as part of a larger project.

Tips for Calculating Yards Accurately

Measure twice — Re-check your form dimensions after building them. Forms can shift or bow.
Account for sub-grade — If your gravel base is uneven, your slab will use more concrete in the low spots. Add 5% extra.
Don’t forget depth variations — Garage floors often have a thicker edge (turn-down footing) that adds significant volume.
Use a concrete calculator — Manual math works, but our free concrete calculator handles unit conversions, waste factor, and multiple zones automatically. Enter dimensions once, get yards, bags, cost, and weight instantly.
Verify with your supplier — Call the ready-mix plant and tell them your project size. They’ll confirm your yardage estimate and can recommend PSI and slump.

Cost of Concrete Per Yard (2026 Prices)

National average pricing for ready-mix concrete:

Standard mix (3,000 PSI): $125–$150/yd³
High-strength (4,000 PSI): $140–$175/yd³
Fiber-reinforced: $155–$190/yd³
Saturday delivery: Add $50–$100 surcharge
Pump truck: $150–$350 (if needed)

Total project cost = (yards × price per yard) + delivery fee + pump (if needed)

Calculate Your Concrete Now

Skip the manual math. Our free concrete calculator instantly shows your project volume in both cubic yards and cubic feet, with bag counts for when bags make more sense. Works for slabs, footings, post holes, walls, columns, stairs, and curbs — all in one tool.