10 ft x 12 ft x 4 in
- Cubic feet
- 44
- Cubic meters
- 1.2459412501
- 80 lb bags
- 74
- 60 lb bags
- 98
Bag counts use common approximate dry-mix yields. Check the exact bag label before buying.
Concrete Calculator
Use this free concrete calculator to estimate slab volume from length, width, depth, waste percentage, cubic yards, cubic meters, and bag counts.
Research-backed assumptions Formula steps Examples included Private in-browser use
Formula steps
- Convert depth from inches to feet.
- Multiply length by width by depth to find cubic feet.
- Add the waste percentage, then divide by 27 for cubic yards.
How to use the concrete calculator
- Enter the requested dates, times, grades, dimensions, network values, password options, or units.
- Check the assumptions shown on the page, especially school scales, payroll rules, concrete waste, subnet type, or security handling.
- Press the calculate button to see the answer, supporting metrics, and formula steps.
- Use examples, recent answers, or copy the result while keeping the estimate limits in mind.
Common uses
Estimate concrete for a simple slab, pad, walkway, or small project.
Convert cubic feet to cubic yards before ordering ready-mix.
Estimate common 40 lb, 60 lb, and 80 lb bag counts.
Add waste percentage before buying materials.
Examples
About 1.63 cubic yards
About 0.98 cubic yards
About 0.41 cubic yards
Frequently asked questions
Quick answers about formulas, inputs, assumptions, examples, copying, and private in-browser use.
What can I use the Concrete Calculator for?
Use it for quick everyday planning, school work, technical checks, or comparison tasks when the inputs match the tool page.
How does the Concrete Calculator calculate the result?
The calculator converts depth from inches to feet, multiplies length by width by depth, adds waste percentage, and converts cubic feet to cubic yards.
What should I double-check before using the answer?
This is a planning estimate. Forms, uneven ground, compaction, reinforcement, waste, truck minimums, and exact bag yield can change what you need.
Are my inputs private?
Yes. The calculator runs in your browser tab. Recent answers stay only on the page while you use it and are not sent to a server.