Calculators
Concrete Calculator
Estimate concrete volume, cubic yards, and premix bags for slabs and round columns locally in your browser.
Enter the pour dimensions in feet to estimate the concrete volume, cubic yards, and premix bags including a waste allowance. An 80 lb bag yields about 0.6 cu ft, a 60 lb bag about 0.45 cu ft, and a 40 lb bag about 0.3 cu ft. The calculation runs locally in your browser; your values are not uploaded or stored.
Find concrete volume and bags without uploading anything.
Enter the pour dimensions in feet or meters, plus a waste allowance and premix bag size, to see the volume, cubic yards, cubic meters, and bags needed. Everything runs locally in your browser, so your values are not uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
What does the concrete calculator show?
Enter the pour dimensions in feet or meters, a waste allowance, and a premix bag size. The calculator returns the volume, the total with waste in cubic feet, cubic yards, and cubic meters, and the number of 80, 60, or 40 lb bags needed. For example, a 10 ft by 8 ft slab 0.5 ft thick is 40 cu ft, which with 10% waste is 44 cu ft (about 1.63 cu yd) and needs 74 bags of 80 lb premix.
Which formulas does the concrete calculator use?
A slab uses volume = length x width x thickness, and a round column or footing uses volume = pi x (diameter / 2)^2 x height. The total with waste is volume x (1 + waste percent / 100). Cubic yards = cubic feet / 27, and bags = total cubic feet rounded up divided by the bag yield (0.6 cu ft for 80 lb, 0.45 cu ft for 60 lb, 0.3 cu ft for 40 lb).
Which inputs are accepted?
Enter dimensions greater than zero through 1000000000 in feet or meters, a waste allowance from 0 to 100 percent (blank means 10), and a bag size of 80, 60, or 40 lb. Decimal values are accepted. Zero, negative numbers, non-numeric text, and values outside these limits show a clear error instead of a result.
Do my numbers stay private?
Yes. The calculation and copy action run locally in your browser. CodeASystem does not upload or store the values you enter.