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Concrete Calculator

How Much Concrete and Rebar Do You Really Need?

How does the calculator work?

  1. Enter your dimensions
    • Length (ft)
    • Width (ft)
    • Depth (in)
  2. Choose your application
    • Sidewalk (≈3,000 PSI)
    • Patio (≈3,500 PSI)
    • Driveway (light vehicle, 3,500 PSI; heavy vehicle, 4,000 PSI)
    • Garage slab (3,500–4,000 PSI)
  3. Get instant results
    • Total concrete volume (yd³), with waste percentage included
    • Rebar required: total feet and pounds, based on spacing and bar size (#3, #4, #5)
    • The PSI strength used for your selected application

Example: Driveway Calculation

Let’s say you’re pouring a 20 × 12 ft driveway at 4 in thickness. With light vehicle use (3,500 PSI):

  • Concrete needed: 3.26 yd³ (with waste included)
  • Rebar required: about 420 ft of #4 bar, ≈280 lb
  • PSI strength: 3,500 PSI

That’s the kind of clarity that keeps projects on track and budgets under control.


Benefits of Using a Concrete Calculator

  • Accurate estimates: eliminate costly guesswork
  • Plan your materials: know concrete volume and steel weight before ordering
  • Save time and money: avoid under-ordering or paying for extra trips
  • Professional image: demonstrate technical knowledge to clients
  • Educational tool: helps homeowners understand why a patio needs 3,500 PSI but a garage slab requires 4,000 PSI

Why this calculator is different

Most online concrete calculators stop at cubic yards. Ours includes:

  • Rebar calculations (feet + pounds)
  • PSI recommendations based on use
  • Waste margin you can adjust from the admin panel

That means you not only know how much concrete to order but also how much reinforcement to prepare.


Limitations & Recommendations

A calculator gives you a strong starting point, but it doesn’t replace field conditions. Final quantities may vary due to:

  • Subgrade conditions
  • Base preparation and compaction
  • Climate and moisture levels
  • Control joints and structural details

Always confirm with a licensed contractor or engineer before placing orders.