How much concrete for a patio?
Concrete patios are usually estimated from the formed patio footprint and planned thickness. Split L-shaped patios, extensions, and landings into separate rectangles for a cleaner estimate.
Patio slab examples
A 10 x 20 ft patio at 4 inches thick is about 2.47 cubic yards before waste. A 16 x 14 ft patio at 4 inches thick is about 2.77 cubic yards before waste.
Patio waste and finish planning
Waste helps cover base variation, forms, and ordering variance. Finish type, slope, control joints, reinforcement, and site prep should be planned separately from concrete volume.
Linear concrete run examples
Examples are before waste. Measure changed-width sections, returns, corners, and transitions separately.
| Project example | Run x width x depth | Cubic yards |
|---|---|---|
| Narrow curb or mow strip | 50 ft x 0.5 ft x 6 in | 0.46 cu yd |
| Standard curb run | 100 ft x 0.5 ft x 6 in | 0.93 cu yd |
| Curb and gutter pan | 100 ft x 1.5 ft x 6 in | 2.78 cu yd |
| Trench or channel fill | 40 ft x 1 ft x 12 in | 1.48 cu yd |
Before you calculate
- Measure the total run length in feet and calculate separate runs when width or depth changes.
- Enter the formed width and thickness instead of using the visible top surface only.
- Keep waste visible for over-excavation, uneven subgrade, short forms, corners, and transitions.
Common mistakes
- Treating a curb or trench like a broad slab and forgetting depth changes along the run.
- Combining straight runs, returns, radiused corners, and driveway transitions without measuring them separately.
- Using a quantity calculator as drainage, reinforcement, slope, or code design.
Formula
cubic yards = (length * width * (thickness / 12) / 27) * (1 + wastePercent / 100)
Assumptions
- Concrete quantity is a planning estimate, not structural design.
- Thickness, forms, subgrade, reinforcement, drainage, slopes, and local requirements should be checked separately.
- Round ready-mix, bags, forms, sealers, and accessories up before ordering.
Example
Estimated concrete needed (cubic yards): 0.98 cubic yards
How to use this calculator
- Enter length in ft.
- Enter width in ft.
- Enter thickness in in.
- Enter waste in %.
- Review the live estimate and compare it with the example result.
- Check the formula, assumptions, product labels, and site conditions before using the Weather Cover Patio Cover Channel Cleanout Platform Concrete Pad Calculator result to plan materials.
Before you buy materials
- Use the result as a ready-mix or bagged-concrete planning number, then round by supplier rules.
- Plan forms, stakes, base, reinforcement, drainage slope, joints, finishing, and cleanup as separate lines.
FAQ
What is the example weather cover patio cover channel cleanout platform concrete pad cubic-yard result?
Use length, width, thickness or depth, and waste, then calculate the planning result. In the default example, the result is 0.98 cubic yards.
How do I calculate concrete for a patio?
Multiply patio length by width, multiply by thickness in feet, divide by 27, then add waste if needed.
How much concrete for a 10 x 20 patio?
At 4 inches thick, a 10 x 20 ft patio needs about 2.47 cubic yards before waste. With 10% waste, plan about 2.72 cubic yards.
Should patio slope be included?
Slope affects layout and drainage more than the basic volume formula. For significant elevation changes or irregular base, calculate sections separately.
Do patio edges or steps change the estimate?
Yes. Thickened edges, steps, landings, and curves should be estimated separately because they add volume.
Related calculators
This calculator is for planning estimates only. Verify final quantities with product labels, project conditions, and a qualified professional when accuracy matters.