Ready Mix Concrete Calculator: How to Estimate Yards, Cost, and Delivery for 2026
Published on 2026-07-01
Ready Mix Concrete Calculator: How to Estimate Yards, Cost, and Delivery for 2026
If you are planning a concrete pour, a ready mix concrete calculator is the fastest way to avoid ordering too much or too little. Ready-mix concrete is delivered by truck and poured on-site, making it the go-to choice for driveways, patios, foundations, and any project over 1 cubic yard. This guide covers how to calculate exactly what you need, what it costs per yard in 2026, and how to avoid the most expensive mistakes homeowners make.
Use our free concrete yardage calculator to get instant results for your project dimensions, then read on for the complete ready-mix ordering playbook.
Quick Answer: How Much Ready-Mix Concrete Do I Need?
Multiply Length (ft) x Width (ft) x Thickness (ft), then divide by 27 to get cubic yards. Always add 10% for waste and uneven subgrade. For a typical 20x20 driveway at 6 inches thick: 20 x 20 x 0.5 = 200 cubic feet / 27 = 7.41 yd3. With 10% waste, order 8.15 cubic yards.
Use our ready mix concrete calculator to run these numbers instantly for any shape or thickness.
Step-by-Step: How to Use a Ready Mix Concrete Calculator
Step 1: Measure Your Area. For rectangles, multiply length x width in feet. For irregular shapes, break the area into smaller rectangles, calculate each separately, and sum the totals. For circular slabs, use: radius x radius x 3.14 = square feet.
Step 2: Convert Thickness to Feet. Divide your thickness in inches by 12. Common conversions: 4 inches = 0.33 ft, 5 inches = 0.42 ft, 6 inches = 0.50 ft, 8 inches = 0.67 ft.
Step 3: Calculate Cubic Feet. Multiply square feet x thickness in feet. Example: 400 sq ft x 0.50 ft = 200 cubic feet.
Step 4: Convert to Cubic Yards. Divide cubic feet by 27. Example: 200 / 27 = 7.41 cubic yards.
Step 5: Add Waste Factor. Multiply by 1.10 for a 10% buffer. Example: 7.41 x 1.10 = 8.15 yd3. Round up to the nearest quarter-yard: order 8.25 cubic yards.
2026 Ready-Mix Concrete Cost Estimate
Ready-mix concrete prices vary by region, but here are the national averages for 2026:
| Concrete Type | Cost per Cubic Yard | Typical Use |
|---|---|---|
| Standard 3,000 PSI | $145 - $165 | Sidewalks, patios, shed bases |
| Standard 3,500 PSI | $155 - $175 | Driveways, garage floors |
| 4,000 PSI | $165 - $190 | Foundations, retaining walls |
| 5,000 PSI | $185 - $215 | Commercial slabs, heavy equipment pads |
| Fiber-reinforced | Add $10 - $15/yd3 | Eliminates wire mesh in slabs |
| Colored / Stamped | Add $50 - $150/yd3 | Decorative patios, pool decks |
For a standard 8.25 yd3 driveway order at 3,500 PSI: 8.25 x $165 = $1,361 for the concrete itself. Total project cost including labor, rebar, grading, and finishing typically runs $8 - $15 per square foot for a complete driveway installation.
Short-Load Fees: The Hidden Cost Most People Miss
Ready-mix trucks carry 8-10 cubic yards at full capacity. If your order is under the truck's minimum (typically 5-6 yards), the supplier charges a short-load fee of $50 to $150 on top of the per-yard price. This can turn a small 2-yard patio pour from $330 into $480 overnight.
How to avoid short-load fees:
- Combine multiple small projects into one pour (patio + walkway + shed base)
- Ask neighbors if they need concrete and split a truck
- For projects under 1.5 yards, bag mix is usually cheaper even with the labor
- Some suppliers offer "small load" trucks (4-5 yard capacity) at a slightly higher per-yard rate but no short-load fee
Ready-Mix vs Bag Mix: When to Choose Each
Choose Ready-Mix When:
- You need 1.5+ cubic yards
- You have truck access to the pour site
- You can pour the entire load within 90 minutes (concrete begins setting after that)
- You have 2-3 helpers ready with wheelbarrows, shovels, and screeds
- You need consistent quality and strength across a large slab
Choose Bag Mix When:
- You need under 1.5 cubic yards
- The pour site has no truck access (backyard, basement, tight urban lot)
- You are working alone or with one helper and need to pour in sections
- You need a small amount for fence posts, mailbox bases, or repair patches
Cost comparison for 2 cubic yards: Ready-mix at $165/yd3 = $330 + $100 short-load = $430. Bag mix: 90 x 80-lb bags at $5.25 each = $473. At 2 yards, ready-mix is slightly cheaper and dramatically faster. At 1 yard, bag mix wins: 45 bags x $5.25 = $236 vs ready-mix at $165 + $100 short-load = $265.
How to Schedule a Ready-Mix Concrete Delivery
1. Call 3-5 days ahead. Concrete suppliers book up fast during construction season (April-October). Call early in the week for a weekend pour.
2. Specify the mix design. Tell them: total yards, PSI strength, slump (typically 4-5 inches for slabs), any additives (fiber, accelerator, retarder, color).
3. Confirm the pour window. Concrete has a 90-minute working window from when water hits the mix. The truck will arrive, you have 90 minutes to place and screed, then finishing begins.
4. Prepare the site before the truck arrives. Forms must be set, graded, and compacted. Rebar or wire mesh must be tied and on chairs. Have a wheelbarrow path cleared if the truck cannot reach the pour directly.
5. Have a Plan B for the extra. Trucks carry slightly more than ordered. Have a small form ready for stepping stones, a mailbox base, or a trash can pad to use any leftover concrete rather than paying a disposal fee.
Common Ready-Mix Concrete Calculator Mistakes
Mistake 1: Forgetting to convert inches to feet. A 20x20 slab at "6" (thinking 6 inches) entered as 6 feet gives 20 x 20 x 6 / 27 = 88.9 yd3 instead of the correct 7.41 yd3. Always divide inches by 12.
Mistake 2: Skipping the waste factor. Uneven subgrade, spillage, and form irregularities consume 5-15% more concrete than the pure geometric calculation. Running short means a cold joint and a structurally compromised slab.
Mistake 3: Ordering by square feet. Concrete is sold by the cubic yard, not the square foot. A 400 sq ft patio at 4 inches needs 4.94 yd3; the same 400 sq ft at 6 inches needs 7.41 yd3. Thickness changes everything.
Mistake 4: Ignoring the subgrade. If your excavation is deeper than planned, you will need more concrete to fill the void. Measure actual depth after excavation, not the planned depth.
Mistake 5: Not accounting for slope. Driveways and patios should slope 1/4 inch per foot for drainage. A 20-foot-long driveway slopes 5 inches from high to low end, adding roughly 0.5 yards to the total.
Ready-Mix Concrete Calculator for Common Projects
| Project | Dimensions | Thickness | Yards Needed | Est. Concrete Cost |
|---|---|---|---|---|
| Small shed base | 10x10 ft | 4 in | 1.36 yd3 | $225 - $300 |
| Single-car driveway | 12x20 ft | 6 in | 4.89 yd3 | $800 - $950 |
| Two-car driveway | 20x20 ft | 6 in | 8.15 yd3 | $1,300 - $1,500 |
| Patio | 16x16 ft | 4 in | 3.48 yd3 | $575 - $675 |
| Garage floor | 24x24 ft | 6 in | 11.73 yd3 | $1,900 - $2,200 |
| Sidewalk (4 ft wide) | 4x50 ft | 4 in | 2.72 yd3 | $450 - $525 |
| Foundation wall | 40 linear ft | 8 in x 4 ft | 3.95 yd3 | $650 - $750 |
Use our ready mix concrete calculator to get exact numbers for your specific dimensions. Every project is different, and a quarter-yard error can mean an expensive short-load or wasted concrete.
What PSI Concrete Do You Need?
PSI (pounds per square inch) measures compressive strength after 28 days of curing. Choosing the right PSI prevents cracking and extends the life of your slab:
- 2,500 PSI: Non-structural applications like curb edging, stepping stones, and small garden pads. Not recommended for anything that bears weight.
- 3,000 PSI: Standard for residential sidewalks, patios, and shed bases. Adequate for foot traffic and light loads.
- 3,500 PSI: The minimum for driveways and garage floors. Handles passenger vehicles without cracking.
- 4,000 PSI: Required for foundations, retaining walls, and any structural application. Also recommended for driveways in freeze-thaw climates.
- 5,000 PSI: Commercial slabs, heavy equipment pads, and industrial floors. Overkill for most residential projects.
Most residential ready-mix orders are 3,000-4,000 PSI. The cost difference between 3,000 and 4,000 PSI is typically $10-20 per yard, a small premium for significantly better durability.
Frequently Asked Questions
How much does a yard of ready-mix concrete cover?
One cubic yard covers 81 square feet at 4 inches thick, 65 square feet at 5 inches, 54 square feet at 6 inches, and 40 square feet at 8 inches. Use our concrete yardage calculator for exact coverage at any thickness.
What is the minimum order for ready-mix concrete?
Most suppliers have a 1-yard minimum, but the practical minimum without a short-load fee is typically 5-6 yards. Orders under 5 yards almost always incur a $50-150 short-load fee. Some suppliers offer small-load trucks with a 3-4 yard minimum at a higher per-yard rate.
How long does ready-mix concrete take to cure?
Concrete sets enough to walk on in 24-48 hours. You can drive a passenger vehicle on it after 7 days. It reaches approximately 70% of its design strength in 7 days and full design strength (the rated PSI) in 28 days. Keep the surface damp for the first 7 days for maximum strength.
Can I pour ready-mix concrete myself?
Yes, for slabs under 10x10 feet with 2-3 helpers. For anything larger, the 90-minute working window makes DIY risky without experience. A 20x20 driveway requires placing, screeding, floating, edging, and broom-finishing 8+ yards in under 90 minutes. Most homeowners hire a crew for pours over 5 yards.
What happens if it rains after pouring concrete?
Light rain within the first 4-6 hours can damage the surface finish. Heavy rain can wash out the cement paste and expose aggregate. Cover fresh concrete with plastic sheeting if rain is forecast. Once concrete has set (4-6 hours), rain actually helps curing by keeping it moist.
Ready-Mix Concrete Calculator: The Bottom Line
A ready mix concrete calculator takes the guesswork out of ordering. The formula is simple: Length x Width x Thickness (in feet) / 27 = cubic yards, plus 10% waste. But the real skill is knowing when to choose ready-mix over bag mix, how to avoid short-load fees, and what PSI to specify for your project.
For most residential projects between 2 and 15 cubic yards, ready-mix is the clear winner on cost, speed, and quality. Use our free concrete calculator to get your exact yardage, then call 2-3 local suppliers for quotes. Prices vary by $20-30 per yard between suppliers in the same city, so shopping around saves real money.
Ready to pour? Check out our complete concrete cost guide for a full project budget breakdown including labor, rebar, permits, and finishing, or use our yardage calculator guide for irregular shapes and multi-section pours.