# Ready Mix Calculator

Ready mix calculator converts slab, footing, or column dimensions to cubic yards of concrete. Compare ready mix truck cost vs bagged concrete with delivery fees.

## What this calculates

A ready mix calculator converts your slab, footing, or column dimensions into cubic yards of concrete to order from a ready mix truck. This calculator handles slabs, continuous footings, cylindrical columns (Sonotube), and stair pours, applies a waste factor for spillage and uneven grade, and estimates the delivered ready mix cost including short-load fees. It also shows the equivalent number of 60 lb and 80 lb bags if you're considering DIY bagged concrete instead.

## Inputs

- **Pour Shape** — options: Slab / rectangular pour, Footing (continuous), Column / cylinder (round), Stair / step (rectangular approx)
- **Length** (ft) — min 0 — For slabs and footings. Ignored for columns.
- **Width** (ft) — min 0 — For slabs. Footing width is typically 12-24 in.
- **Thickness / Depth** (in) — min 0 — 4 in standard slab. 12 in typical for residential footing.
- **Column Diameter** (in) — min 0 — Only used for column/cylinder shape. 10-12 in Sonotube common.
- **Column Height** (ft) — min 0 — Only used for column/cylinder shape.
- **Quantity** — min 1, max 200 — Number of identical pours (useful for multiple footings or columns).
- **Waste Factor** (%) — min 0, max 30 — Typical 10% for slabs, 15-20% for footings with rough grade.
- **Include Delivery Pricing** — Shows estimated ready mix delivery cost (US average $130-175/yd).
- **Concrete Strength (PSI)** — options: 2,500 PSI (non-structural), 3,000 PSI (residential slab, patio), 3,500 PSI (driveway, garage slab), 4,000 PSI (foundation, commercial), 5,000 PSI (structural, high load) — PSI affects ready mix price: each 500 PSI up adds $5-10/yd.

## Outputs

- **Concrete Volume** (cu ft)
- **Ready Mix Cubic Yards** (yd³) — Order this many cubic yards of ready mix.
- **Round Up to Order** (yd³) — Rounded up to the nearest 1/4 yd (typical order increment).
- **80 lb Bag Equivalent** — If bagging it instead of ready mix.
- **60 lb Bag Equivalent**
- **Estimated Ready Mix Cost** — formatted as currency — Includes short-load fee if applicable.
- **Bagged Concrete Cost (80 lb)** — formatted as currency — At $6 per 80 lb bag for comparison.

## Details

## How the Ready Mix Calculator Works

The ready mix calculator converts your pour dimensions to cubic yards:

- **Rectangular pours** (slab, footing, stair): length x width x thickness (in feet)
- **Cylindrical pours** (column, Sonotube): pi x radius^2 x height

Then:

- **Cubic yards = cubic feet / 27**
- Apply 10-20% waste factor for spillage, over-dig, and uneven grade
- Round up to the nearest 0.25 cubic yard (typical ready mix order increment)

## Common Ready Mix Pours

| Pour | Dimensions | Cubic Yards |
|------|------------|-------------|
| 10x10 4 in slab | 100 sqft, 4 in | 1.23 yd |
| 20x20 4 in slab | 400 sqft, 4 in | 4.94 yd |
| 24x24 garage slab | 576 sqft, 4 in | 7.11 yd |
| Driveway 12x50 6 in | 600 sqft, 6 in | 11.11 yd |
| Footing 1.5 ft x 1 ft x 50 ft | standard | 2.78 yd |
| 10 in Sonotube x 4 ft | 18 columns for deck | 6.55 yd |

## Ready Mix Concrete Price (2025)

Ready mix concrete price ranges $130-175 per cubic yard for 3,000 PSI in 2025, depending on region and volume. Pricing structure:

- **Base:** $130-155/yd for 3,000 PSI standard mix
- **Each 500 PSI above 3,000:** adds $5-10/yd
- **Short-load fee:** under 5 yd adds $15-30/yd, under 3 yd adds $30-50/yd
- **Delivery trip fee:** $100-150 per truck
- **Saturday / overtime:** $50-100 surcharge
- **Long pours** (slow unload over 45 min): $50-100/truck

A typical 10 yd pour of 3,500 PSI for a driveway costs $1,500-1,900 delivered. A 3 yd short load for a patio costs $625-775 delivered (disproportionately expensive per yard).

## Ready Mix Truck Volume

A standard ready mix truck holds 8-11 cubic yards. Small mini-mixers hold 4-6 yd. Concrete must be placed within 90 minutes of leaving the batch plant (cement starts hydrating immediately). If your pour takes longer than one truck can deliver, schedule two trucks 30-60 minutes apart.

## Ready Mix vs Bagged Concrete Cost

When to use ready mix vs bags:

- **Ready mix:** cheaper per cubic yard above 1-2 yd total. Always cheaper for pours over 5 yd.
- **Bags:** easier for very small pours (under 0.5 yd), fence posts, small repairs. $6 per 80 lb bag at Home Depot. One 80 lb bag = 0.6 cubic feet. To match 1 cubic yard, you need 45 bags = $270 vs $230-250 for 1 yd delivered.

For anything over 1 yard, ready mix beats bags on both cost and labor.

## Ready Mix PSI Guide

Use the right PSI for the pour:

| PSI | Application | Price Premium |
|-----|-------------|---------------|
| 2,500 | Fill, non-structural | -$5/yd |
| 3,000 | Interior slab, patio | baseline |
| 3,500 | Driveway, garage slab | +$8/yd |
| 4,000 | Foundation wall, footing | +$15/yd |
| 5,000 | Structural column, heavy load | +$25/yd |

## Slab Thickness Guidelines

- **Patio / walkway:** 3-4 in
- **Residential floor:** 4 in
- **Driveway:** 4-6 in (6 in for heavy vehicles or clay soil)
- **Garage slab:** 4-6 in
- **Commercial slab:** 6-8 in minimum, rebar or mesh
- **Footings:** 8-16 in depth, below frost line (24-48 in in cold climates)

## Placing the Order

When ordering ready mix:

1. Call 2-3 days ahead (1 week for large orders)
2. Tell them the exact PSI, slump (typically 4-5 in for residential), and additives (air entrainment for freeze-thaw, fiber for cracking control)
3. Give them an accurate yardage - under-ordering forces a second trip fee
4. Prepare the site: forms set, rebar in place, gravel base compacted
5. Have 2-3 strong helpers ready to place, screed, and float immediately

## Waste Factor Guidance

- **Slab on flat gravel base:** 5-10% waste
- **Footing with uneven trench:** 15-20%
- **Multiple columns or piers:** 10% per column
- **Curbing or complex pours:** 15%

Never under-order. Running out of concrete mid-pour requires calling for a second (expensive) truck or abandoning the pour.

## Frequently Asked Questions

**Q: How does a ready mix calculator work?**

A: A ready mix calculator multiplies your length, width, and thickness (all in feet) to get cubic feet, then divides by 27 to get cubic yards. For cylinders (Sonotube columns), it uses pi x radius squared x height. It then applies a 10-20% waste factor and rounds up to the nearest 0.25 cubic yard (typical order increment). A 10x10 slab at 4 in thick = 100 x 0.333 = 33.3 cubic feet = 1.23 cubic yards.

**Q: How much does ready mix concrete cost?**

A: Ready mix concrete cost averages $130-175 per cubic yard for 3,000 PSI in 2025. Delivered cost for a 10 yd pour is $1,500-1,900 including delivery. Short-load fees apply to orders under 5 yd: $15-30/yd extra under 5 yd, $30-50/yd extra under 3 yd. Each 500 PSI above 3,000 adds $5-10/yd. Saturday and overtime add $50-100 per truck.

**Q: How many cubic yards is a 10x10 slab at 4 inches thick?**

A: A 10x10 slab at 4 inches thick is 1.23 cubic yards of concrete before waste factor. With a 10% waste factor, order 1.36 cubic yards. Since most ready mix plants have a 1-yard minimum, either order 1.5 yards from ready mix or mix 60 80-lb bags ($360 at $6/bag) for a DIY pour.

**Q: What is the short-load fee on ready mix?**

A: Short-load fees apply to ready mix orders under 5 cubic yards because the truck is underutilized. Typical fees: under 5 yd adds $15-30/yd, under 3 yd adds $30-50/yd. A 3 yd pour effectively costs $170-190/yd delivered vs $140-155/yd for a full 10 yd load. For very small pours, bagged concrete is cheaper.

**Q: How many 80 lb bags of concrete equal a cubic yard?**

A: One 80 lb bag of concrete yields 0.60 cubic feet, so 45 bags make 1 cubic yard (27 / 0.60 = 45). At $6 per 80 lb bag, a DIY cubic yard costs about $270 plus labor. Ready mix for the same cubic yard is $140-175 plus $100 delivery. For 1 cubic yard or more, ready mix is cheaper and faster. Use bags only for pours under 0.5 cubic yard or where a truck cannot access the site.

**Q: What PSI concrete should I order for a driveway?**

A: For a residential driveway, order 3,500 PSI concrete with 4-6 inches thickness. For commercial or heavy-vehicle driveways, use 4,000 PSI. In freeze-thaw climates, add air entrainment (4-7% air content) to prevent scaling. Rebar or wire mesh is recommended for driveways to control cracking; rebar adds more than mesh but lasts longer.

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Source: https://vastcalc.com/calculators/construction/ready-mix
Category: Construction
Last updated: 2026-04-08