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Concrete Calculator

Calculate how much concrete you need. Enter dimensions to get cubic yards, number of bags, and estimated material cost.

Dimensions

Cubic Yards Needed

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Cubic Feet

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60 lb Bags

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80 lb Bags

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Estimated Cost

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Notes

  • A 60 lb bag of concrete yields approximately 0.45 cubic feet
  • An 80 lb bag yields approximately 0.60 cubic feet
  • For ready-mix delivery, minimum order is typically 1 cubic yard
  • Waste factor of 5-10% is recommended to account for spillage and uneven ground
  • Standard slab depth: 4" for patios/walkways, 6" for driveways

Adds your concrete materials line to the Construction Estimate Builder — combine with labor + other trades to build a bid.

Concrete Ordering Guide

1

Measure Your Project

For slabs: measure length, width, and depth. For columns: measure diameter and height. Always round up dimensions to account for form variations and spillage.

2

Bags vs. Ready-Mix

Under 1 cubic yard: use bags (more flexible, no minimum). Over 1 yard: ready-mix truck is more economical. Most trucks carry 8-10 cubic yards. Short-load fees apply under 3 yards.

3

Understand PSI Ratings

2,500 PSI: walkways, patios. 3,000 PSI: driveways, slabs. 3,500 PSI: foundations. 4,000+ PSI: commercial, heavy traffic. Higher PSI costs more but lasts longer.

Common Project Depths

4 inches - Sidewalks, patios, garden paths. Standard for pedestrian traffic only. Use 3,000 PSI mix.
6 inches - Driveways, garage floors. Supports vehicle weight. Use 3,500 PSI with fiber mesh or wire mesh reinforcement.
8-12 inches - Foundation walls, footings. Must meet local building codes. Requires rebar reinforcement on 12-16" centers.
36-48 inches - Column footings, pier footings. Depth depends on frost line. Use sonotube forms for cylindrical pours.

Frequently Asked Questions

How much does concrete cost?

Ready-mix: $120-$180 per cubic yard delivered. Bags: 60lb bag ($4-$5) covers 0.45 cu ft; 80lb bag ($5-$7) covers 0.60 cu ft. For large projects, ready-mix is 30-50% cheaper.

How long does concrete take to cure?

Initial set: 24-48 hours (can walk on it). Full strength: 28 days. Keep moist for first 7 days for optimal curing. Avoid pouring below 40F or above 90F.

Do I need rebar or wire mesh?

4" slabs: wire mesh or fiber is sufficient. 6"+ driveways: #4 rebar on 12-18" grid. Footings: always use rebar per local code. Rebar prevents cracking under stress.

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