Readymix Calculator

For any concrete project much bigger than a few bags, the smart move is ready-mix: concrete batched at a plant and delivered in a mixer truck, arriving uniform, on-spec, and ready to place. But ordering ready-mix means answering the supplier's questions precisely — how many cubic yards, how many trucks, what mix — and knowing the full cost before the truck rolls. The Readymix Calculator plans the entire order. Enter your slab's length, width, and thickness plus the supplier's price per cubic yard and delivery fee per truck, and it reports the cubic yards (including a 10 percent waste allowance), the mixer trucks needed, material cost, delivery cost, total project cost, and cost per square foot. This tool is for homeowners ordering their first ready-mix load, contractors preparing bids, and anyone comparing ready-mix against bagged concrete. It is also useful for budgeting, since the per-square-foot figure lets you sanity-check quotes against typical local pricing. In this guide, you will learn how ready-mix ordering works, how to use the calculator step by step, and what the numbers look like in two fully worked examples. You will also learn the ordering math, the factors that affect your load, and practical tips for a smooth delivery day.

What Is Ready-Mix Concrete Ordering?

Ready-mix concrete is concrete manufactured at a batch plant to a specified mix design, transported in a revolving-drum mixer truck, and discharged at your site while still plastic. It is sold by the cubic yard — a mixer truck typically carries 8 to 10 cubic yards — and priced per yard plus delivery fees. Ordering has four parts. First, the quantity: your slab's volume in cubic yards plus a waste allowance (10 percent is standard) to cover spillage and subgrade variation. Suppliers generally require minimum loads of 1 to 3 yards and charge short-load fees below that. Second, the mix design: the strength (e.g., 3000 or 4000 psi), aggregate size, and any admixtures, matched to the application. Third, the logistics: how many trucks the quantity requires (each carrying about 10 yards), site access for a heavy truck, and scheduling so the crew is ready when concrete arrives — you typically get limited free unloading time. Fourth, the cost: material (yards × price per yard) plus delivery fees per truck, which is exactly what the calculator totals. A concrete illustration: a 20×15 ft patio at 4 inches thick needs 100 cubic feet, or 3.70 cubic yards — 4.07 with waste. That fits in one 10-yard truck. At $140 per yard plus a $75 delivery fee, the material costs $570.37, delivery $75, for a total of $645.37, or $2.15 per square foot.

Why Planning Your Ready-Mix Order Matters

Under-ordering ready-mix is a disaster measured in hundreds of dollars and a ruined slab. A second truck dispatched mid-pour arrives too late — the first load has begun setting, creating a cold joint that weakens the slab and shows forever. The 10 percent waste allowance in the calculator exists specifically to prevent this: it is far cheaper than a short load. Over-ordering wastes money differently. Suppliers charge for every yard batched, and many charge a washout or return fee for concrete brought back. Ordering a full truck when you needed half means paying for concrete you will literally throw away. Accurate yardage threads the needle between these two expensive errors. Cost transparency is the third reason. Ready-mix quotes bundle material, delivery, fuel surcharges, and sometimes standby time; the calculator's line-by-line breakdown lets you verify a supplier's quote and compare suppliers fairly. The cost per square foot is especially useful — if one quote works out to $2.15 per square foot and another to $3.50 for the same slab, you know to ask questions.

How to Use the Readymix Calculator

Follow these steps:

1. Step 1: Enter the length and width. Type the slab dimensions in feet into the "Length (feet)" and "Width (feet)" fields, for example 20 and 15.
2. Step 2: Enter the thickness. Type the thickness in inches into the "Thickness (inches)" field, for example 4.
3. Step 3: Enter the price per cubic yard. Type your supplier's material price into the "Price per Cubic Yard" field, for example 140. Call suppliers for current local pricing.
4. Step 4: Enter the delivery fee per truck. Type the delivery charge into the "Delivery Fee per Truck" field, for example 75. Ask whether fuel surcharges apply on top.
5. Step 5: Click Calculate. The calculator shows yards with waste, trucks needed, material and delivery costs, total cost, and cost per square foot. Click Reset to clear the form and plan another pour.

Worked Example 1: 20 × 15 ft Patio, 4 in Thick

You are ordering ready-mix for a 20×15 ft patio, 4 inches thick. The supplier charges $140 per cubic yard with a $75 delivery fee per truck. Step 1 — Volume in cubic feet. 20 × 15 × (4/12) = 100.00 cubic feet. Step 2 — Cubic yards with 10% waste. (100.00 / 27) × 1.10 = 4.07 cubic yards. Step 3 — Trucks needed. 4.07 / 10 = 0.41, rounded up to 1 truck. Step 4 — Material cost. 4.07 × $140 = $570.37. Step 5 — Delivery cost. 1 × $75 = $75.00. Step 6 — Total and per square foot. $570.37 + $75.00 = $645.37 total; $645.37 / 300 sq ft = $2.15 per square foot. The final result: one truck delivering 4.07 yards costs $645.37 all-in — far cheaper and faster than mixing the equivalent 68 eighty-pound bags by hand.

Worked Example 2: 40 × 30 ft Warehouse Slab, 6 in Thick

You are ordering for a 40×30 ft slab, 6 inches thick, at $150 per yard with an $85 delivery fee per truck. Step 1 — Volume in cubic feet. 40 × 30 × (6/12) = 600.00 cubic feet. Step 2 — Cubic yards with 10% waste. (600.00 / 27) × 1.10 = 24.44 cubic yards. Step 3 — Trucks needed. 24.44 / 10 = 2.44, rounded up to 3 trucks. Step 4 — Material cost. 24.44 × $150 = $3,666.67. Step 5 — Delivery cost. 3 × $85 = $255.00. Step 6 — Total and per square foot. $3,666.67 + $255.00 = $3,921.67 total; $3,921.67 / 1,200 sq ft = $3.27 per square foot. The final result: three trucks, $3,921.67 total — a pour that needs a crew, a schedule, and trucks spaced so each load arrives as the previous one is placed.

Understanding the Ordering Math

The calculator's quantity math is volume plus waste: cubic yards = (length × width × thickness in feet) / 27 × 1.10. The 10 percent waste factor covers spillage, subgrade low spots, and form spread — the standard allowance in the trade. Trucks are then computed at 10 cubic yards of capacity each, rounded up, since a partial truck still requires a full truck trip. The cost math separates material (yards × price per yard) from delivery (trucks × fee per truck). This split matters because the two scale differently: material grows smoothly with yardage, while delivery jumps in steps each time you cross a truckload boundary. A 10.5-yard order needs two trucks and two delivery fees — a detail that surprises first-time buyers and that the calculator surfaces automatically. The cost per square foot divides the all-in total by the slab area, producing the single number most useful for comparing quotes and benchmarking against local norms. Residential flatwork commonly lands in the $2 to $5 per square foot range for materials; far outside that band deserves a second look.

Key Factors That Affect Your Order

Subgrade preparation drives real yardage. Soft or uneven ground consumes the waste allowance quickly — on poor subgrade, consider raising the allowance mentally or fixing the base before the truck arrives. Compacted, level subgrade keeps actual use close to theoretical volume. Access and scheduling are the logistical factors. A mixer truck is heavy and needs firm, wide access; soft ground or tight turns may require a pump truck (extra cost) or wheelbarrow relays (extra labor and time). Schedule trucks with spacing — typically 20 to 30 minutes apart — so each load arrives as the crew finishes placing the previous one. Mix specification affects price per yard: higher strengths, smaller aggregate, fiber reinforcement, and admixtures (retarders for hot weather, accelerators for cold) each add cost. Confirm the mix with your supplier when getting the per-yard price you enter into the calculator.

Tips for a Smooth Ready-Mix Delivery

1. Confirm the per-yard price, delivery fee, and any fuel or short-load surcharges in writing.
2. Have forms set, braced, and inspected the day before — the truck will not wait for carpentry.
3. Arrange enough crew: placing and finishing 4 yards needs at least 3 to 4 experienced people.
4. Verify truck access the day before; soft ground may need planks or a pump.
5. Keep the supplier's phone number handy to adjust truck spacing on pour day.
6. Test the first wheelbarrow's slump — it should match what you ordered before full discharge.
7. Never add excessive water at the site; it permanently weakens the concrete.
8. Plan curing in advance: have sprinklers, hoses, or curing compound ready.
9. Tip the driver for a difficult placement — goodwill matters on multi-truck pours.

Frequently Asked Questions

1. What does the Readymix Calculator tell me? It plans a complete ready-mix order: cubic yards including 10 percent waste, the number of 10-yard mixer trucks needed, material cost, delivery cost, total project cost, and cost per square foot.

2. How many cubic yards do I need? Multiply length × width × thickness (in feet) and divide by 27, then add 10 percent waste. The calculator does this in one step — 100 cubic feet becomes 4.07 yards in the patio example.

3. How much does a mixer truck hold? Typically 8 to 10 cubic yards. The calculator uses 10 yards per truck, the common full-load figure. Confirm your supplier's truck capacity when ordering.

4. What does ready-mix cost per yard? Typically $120 to $180 per cubic yard for standard residential mixes, varying by region and mix design. Delivery fees, fuel surcharges, and short-load fees add on top — get an all-in quote.

5. What is a short-load fee? A surcharge for orders below the supplier's minimum (often 2 to 4 yards), covering the cost of sending a truck partly empty. Small orders can carry fees of $50 to $150 or more per load.

6. How much unloading time do I get? Usually 30 to 60 minutes free per truck, then standby charges accrue. Have the crew and tools ready before the truck arrives — the meter runs on delays.

7. Ready-mix versus bags — which is cheaper? Past roughly 2 cubic yards, ready-mix is almost always cheaper per yard and enormously faster. The 4.07-yard patio example costs $645 ready-mix versus far more in bags plus a day of mixing labor.

8. What mix strength should I order? 3000 psi suits most residential flatwork; 4000 psi for driveways and structural work. Your supplier will recommend the right mix — specify the application when ordering.

9. Can the truck reach my backyard? Mixer trucks need firm, wide access — typically 10 to 12 feet wide with overhead clearance. If access is impossible, options include a pump truck, conveyor, or wheelbarrow relay, each adding cost or labor.

10. How accurate is the yardage estimate? Very accurate for the dimensions entered, with the 10 percent waste allowance covering normal variation. Poor subgrade can exceed the allowance — prepare the base well to keep actual use on target.

11. What happens if I order too much? You pay for every yard batched, plus possible return fees for concrete brought back. Some suppliers allow small overages to be placed in a pre-dug waste pit — ask about their policy when ordering.

12. Should I order in the morning? Yes, especially in warm weather. Morning pours give the crew the full day for placing and finishing before the heat accelerates the set. Schedule the first truck as early as the plant allows.

13. What is slump and why does it matter? Slump measures workability — a 4 to 5-inch slump is typical for slabs. Order the right slump for the job and resist adding water on site, which raises slump but permanently weakens the concrete.

14. Do I need to be present for delivery? Someone knowledgeable must be on site to direct the driver, confirm the mix, and manage placement. Never leave a delivery to an unprepared helper — mistakes made in the first ten minutes last for decades.

15. How do I compare two suppliers' quotes? Reduce each to the calculator's line items: price per yard, delivery fee per truck, surcharges, and minimums. The total project cost and cost per square foot reveal the real cheapest option.

CONCLUSION

The Readymix Calculator takes the uncertainty out of ordering concrete by the truckload: exact yardage with waste, truck count, and a line-by-line cost down to the dollar per square foot. It is the difference between calling the plant with confidence and hoping the numbers work out. The single most important takeaway: order accurately, include the waste allowance, and have the site ready before the truck arrives. Ready-mix is the best concrete deal available for mid-size and large pours — but only when the quantity is right and the crew is waiting.