Concrete Calculator
Calculate concrete volume, weight, and material requirements for construction projects.
Project Details
Concrete Specifications
Reinforcement
Pricing
Concrete Volume
146.7 ft³
Total Project Cost
Materials + Labor
Cost per Sq Ft
Project cost density
Materials Cost
Concrete + Rebar
Labor Cost
10.9 hours
Project Summary
Project Guidelines
- • Allow 7 days for initial curing, 28 days for full strength
- • Keep concrete moist during curing process
- • Order concrete early morning for best workability
- • Have all tools and crew ready before delivery
- • Check weather conditions before pouring
How it works
A concrete calculator finds the volume of concrete a slab, footing, or column needs. You multiply length by width by thickness to get cubic feet, then convert to cubic yards (the unit concrete is sold in) by dividing by 27.
Concrete volume
Cubic feet = length × width × thickness Cubic yards = cubic feet ÷ 27
- length, width
- slab dimensions in feet
- thickness
- depth in feet (4 in = 0.333 ft)
Worked example
- Slab 10 ft × 10 ft
- 4 inches thick = 0.333 ft
- Cubic feet = 10 × 10 × 0.333 = 33.3
- Cubic yards = 33.3 ÷ 27
≈ 1.23 cubic yards — order ~1.35 yd³ to allow for waste.
Good to know
- Add about 5–10% for spillage, uneven subgrade, and over-excavation.
- Convert the thickness to feet first (inches ÷ 12) before multiplying.
- Ready-mix is sold by the cubic yard; bagged concrete lists how many bags make a cubic foot.
Related Calculators
Frequently Asked Questions
How accurate are the calculations?
Our calculators use industry-standard formulas and algorithms, regularly tested for accuracy. For critical decisions, verify with professionals.
Can I save my calculations?
You can bookmark pages with your inputs, take screenshots, or use your browser's print function to save results for future reference.
Is my data private?
All calculations happen in your browser. We don't store or transmit your input data, ensuring complete privacy.
How much extra material to order?
Add 5-10% for simple projects, 10-15% for complex patterns. Some materials need extra for future repairs.
When are permits required?
Most structural changes, electrical, and plumbing work need permits. Check with local building department.
DIY or hire professionals?
Consider skill level, time, and complexity. Structural, electrical, and plumbing often require licensed pros.
How to estimate timeline?
Research typical durations, add buffer for weather/delays, consider drying times, and be realistic about work hours.