Concrete Calculator
Get cubic yards, the cost of ready-mix delivered, the weight, and how many bags you need. Built for contractors and serious DIYers.
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Standard slab is 4 inches. Driveway is 4 to 6 inches. Garage floor is 4 inches.
Ready-mix concrete typically runs $125 to $200 per cubic yard delivered. Add a short-load fee if you need less than a full truck.
Order 5 to 10 percent extra for spillage, uneven subgrade, and over-excavation.
Your result
At $175.00 per cubic yard delivered
- Volume needed66.7 cubic feet
- 2.47cubic yards
- With 10% wasteRound up to the next quarter yard when ordering ready-mix.
- 2.72cubic yards
- Weight of concrete5 tons
- 10,000lbs
- 80 lb bags (if mixing yourself)Or 149 of the 60 lb bags. Bagged concrete only makes sense for jobs under ~1 cubic yard.
- 112bags
Example. A 20 ft by 10 ft patio at 4 inches thick is 2.47 cubic yards. With 10% waste, order 2.72 cubic yards. At $175 per yard, that is around $476 in concrete.
Save this as a free estimateHow thick should the slab be?
The right thickness depends on what the slab is for. Use these as a starting point and confirm with local building code.
- Patios, walkways4 in
- Garage floors (residential)4 in
- Garage floors (heavy vehicles)6 in
- Residential driveways (cars)4 in
- Residential driveways (trucks, RVs)5-6 in
- Shed and shop floors4-6 in
- FootingsTypically twice as wide as the wall they support.8 in
Always pour over a compacted gravel base. Skipping the base is how cracks form within the first winter.
What concrete actually costs
Ready-mix concrete prices vary by region and by truck volume. These are typical 2026 ranges before fees.
Watch for these add-ons that surprise first-timers:
- Short-load fee: roughly $40 to $60 per cubic yard short of the full-truck minimum (about 9 to 10 yards), so a small 2-yard order can add $200 to $400
- Saturday or after-hours delivery: $75 to $200 extra
- Long wait time: the driver bills $1 to $3 per minute after the included unload time
- Fuel surcharge: common, varies by supplier
Get quotes from two or three local ready-mix plants. Prices move week to week with fuel and cement costs.
When to mix it yourself with bagged concrete
Bagged concrete makes sense for jobs under about a cubic yard. Past that, the math (and your back) say to call a truck.
- A 60 lb bag of concrete mix makes about 0.45 cubic feet.
- An 80 lb bag makes about 0.6 cubic feet.
- One cubic yard (27 cubic feet) is about 60 of the 60 lb bags or 45 of the 80 lb bags.
At roughly $5 to $7 per bag, mixing 60 bags of 80 lb concrete by hand costs $300 to $420 and a full day. A truck delivers the same volume for $150 to $200 and pours in 15 minutes. Bags win for fence post holes and small repairs. Trucks win for slabs.
Pricing the job to the client
The cost of concrete is just material. To turn this into a client estimate, add labor, equipment, finishing, and your contractor markup on top. Most concrete contractors apply a 20 to 40 percent markup on materials and price labor at a separate hourly or per-square-foot rate. The markup calculator converts your raw cost into the right selling price, and our construction estimate template gives you a one-page format you can hand to the client.
For a deeper read on costing out a concrete job, see our guides on estimating construction costs and how to calculate profit margins on construction jobs.
How do you calculate cubic yards of concrete?
Use the calculator above. Enter the length and width in feet, the thickness in inches, and you get cubic yards with a waste factor already added. For a quick reference: a 12 ft by 12 ft slab at 4 inches thick is about 1.78 cubic yards before waste. Always order 5 to 10 percent extra to cover spillage and uneven subgrade.
How much concrete do I need for a 10x10 slab at 4 inches thick?
A 10 ft by 10 ft slab at 4 inches thick needs 1.23 cubic yards. With a standard 10 percent waste factor, order 1.35 cubic yards. That is about 61 of the 80-pound bags if you mix it yourself (1.35 × 45 per yard), or a short-load delivery from a ready-mix truck.
How many 80 lb bags of concrete in a yard?
About 45 of the 80-pound bags equal one cubic yard. 60 lb bags need about 60 bags per yard, and 40 lb bags need 90 bags per yard. The math: one 80 lb bag yields roughly 0.6 cubic feet, and a cubic yard is 27 cubic feet.
How much does a concrete driveway cost?
A residential concrete driveway runs $6 to $12 per square foot installed in 2026 for a basic 4-inch slab. That includes labor, the ready-mix concrete, basic forming, and a broom finish. Stamped or colored concrete adds $5 to $15 per square foot. For a typical 600 sq ft driveway, expect $3,600 to $7,200 for plain concrete.
Why does my concrete order seem too small?
Two common reasons. First, the thickness was entered as inches instead of feet. A 4 inch slab needs the calculator to use 0.333 feet, not 4. Second, no waste factor was added. Always order 5 to 10 percent more than the raw calculation. Spillage at the truck, uneven subgrade, and over-excavation eat the rest.
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