Project ticket
How much concrete for a 16x20 patio?
Initial example: a 16x20 ft patio at 4in depth with 10% waste needs 196 bags of 80lb premix, 261 bags of 60lb premix, or 4.35 cu yd of concrete. These are alternative supply options. The calculator below starts with this example; adjust it for your project.
For rectangular volumes. Use the depth specified for your project; this calculator estimates material quantity, not structural design.
Quantities to confirm
Concrete purchase sheet
The starting yield is an example for this bag size. Replace it with the product label; bag weight alone does not determine yield.
- 80 lb bags117.333 cu ft with allowance ÷ 0.6 cu ft per bag; rounded up.
- 196bags
What this estimate assumes
- Raw volume: 106.667 cu ft. Waste allowance: 10%.
- Rectangular volume only; the entered depth comes from your design.
- Bag yield entered: 0.6 cu ft/bag. Whole bags provide 0.267 cu ft above the volume with allowance.
- Only the selected supply method is listed; alternatives are not added together.
Name your project & add notes Optional
Includes your quantities, assumptions and space to record the supplier, confirmed quantity, quote and delivery. No account required.
How to check this list before buyingCompare standard bag sizes and volume
Material totals
1 cu yd = 27 cu ft. Bag counts are rounded up to whole bags; volumes are displayed to two decimal places. The two bag sizes are alternatives.
Concrete shopping list
Choose one supply method; do not add these quantities together.
Yield assumptions: one 80lb bag = 0.6 cu ft; one 60lb bag = 0.45 cu ft. Check the actual bag label; products can differ.
The volumes above include the stated waste allowance. Confirm yield, ready-mix ordering increments and delivery requirements with your supplier before purchasing.
BuildTotals.com · Prepared: __________ · buildtotals.com/tools/concrete-calculator
The example volume is 106.67 cu ft before waste and 117.33 cu ft with 10% waste. Bag counts round up to whole bags using the calculator's stated yields.
Use the depth specified for your actual design. Compare supplier quotes for bagged mix and ready-mix, including delivery minimums, access, and placement needs. Confirm the bag yield or final delivery quantity with your supplier before ordering.