Calculated result
3.25yd³
Ready-mix order
Formula
CONC-PATIO-001L × W × D × quantity ÷ 27 × (1 + waste) → ready-mix order
80 ft³
Net volume
2.96 yd³
Net volume
0.33 loads
10 yd³ truck-load equivalent
Concrete calculator
Concrete patio calculator
Patio slab volume, ready-mix order and bag-equivalent estimate with visible allowance.
By Feroz Sheikh · Formula CONC-PATIO-001 v1.1.0 · Tested formula
Formula
CONC-PATIO-001v1.1.0Project inputs
Enter your measurements. Switching units converts the same project, including coverage and unit rates. Package yields keep the unit printed beside each field.
Refine measurements and rates at any time. Your current values are included in the material-list PDF.
Planning estimate, not engineering advice. Confirm site measurements and product specifications. Calculation limits.
Bag table · waste in
Counts round up. A cubic yard is 45 of 80 lb, 60 of 60 lb, 72 of 50 lb, 90 of 40 lb.
| Bag | Count |
|---|---|
| 40 lb | 288 |
| 50 lb | 231 |
| 60 lb | 192 |
| 80 lb | 144 |
Use finished patio dimensions and thickness to calculate net volume, allowance and ready-mix purchase quantity transparently.
- Measure finished patio length and width.
- Enter the concrete thickness required by the final project design.
- Use the order quantity as a planning baseline before supplier and site review.
Add your project costs
Enter supplier prices and any labour, equipment or delivery costs. Pick a currency — badges, inputs, and totals follow.
Enter your supplier’s ready-mix concrete rate in the selected unit. Add delivery, pumping, short-load fees and placing labour as separate project costs. For GCC projects, select QAR, AED, SAR, KWD, OMR or BHD and enter local supplier rates.
How this calculator works
A transparent concrete patio takeoff.
Feroz SheikhWritten by Feroz Sheikh · founder
Use finished patio dimensions and thickness to calculate net volume, allowance and ready-mix purchase quantity transparently.
A patio is a slab with different joints and often a 4 in default. Driveway thickness does not belong here. Control joints and broom finish stay off the volume line.
Worked example. Example: a 20 ft × 12 ft patio at 4 in depth contains 2.96 yd³ before allowance; with 8% waste it rounds to 3.25 yd³.
See the example inputs and calculated result
This separate example uses the calculator's starting values in imperial units. It stays unchanged when you edit the tool above. Example rates, yields and dimensions are assumptions, not recommendations for your project.
| Input | Example value |
|---|---|
| Patio length | 20 ft |
| Patio width | 12 ft |
| Concrete depth | 4 in |
| Waste factor | 8 % |
Example result: Ready-mix order — 3.25 yd³.
L × W × D × quantity ÷ 27 × (1 + waste) → ready-mix order
Use the labelled units above when reproducing this example. To work in metric, switch the calculator to Metric; applicable measurements are converted, while product-specific units remain labelled.
- 1. Measure finished patio length and width.
- 2. Enter the concrete thickness required by the final project design.
- 3. Use the order quantity as a planning baseline before supplier and site review.
Field notes that change the number
- Measure the finished pad, including any radius as a circle takeoff or a split rectangle.
- Steps and seating walls are extra prisms.
- Base rock is landscaping gravel, not extra concrete.
Common mistakes
- Using a 5–6 in driveway thickness on a patio.
- Forgetting the thickened edge as its own volume.
- Ordering colour or fibre in the yard rate without saying so.
Need the broader workflow? Read the concrete planning guide.
How-to: Concrete slab cost: build an estimate from supplier quotes
Questions
Questions about concrete patio
Does it determine reinforcement or joint spacing?
No. This calculator only estimates volume; construction detailing needs independent review.
Why use an allowance?
Placement, spill and field variation can make a pure net-volume order too small.
What is the formula ID?
This concrete patio calculator publishes formula CONC-PATIO-001, version 1.1.0. The ID stays on the result and on the estimate line.