What is the 1 2 3 concrete mix ratio?

Construction & MaterialsStandard Concrete Proportions

Concrete Mixing Ratio Calculator (1:2:3 Recipe)

Calculate exact quantities of Portland cement bags, sand tons, gravel tons, and water gallons for standard 1:2:3 recipe concrete mixes.

Construction & Materials Field StandardsStandard Concrete Proportions

Engineering formulations calibrated to IPC, UPC & NEC specificationsSub-Zero Cold Climate Tolerances

Quick Summary & Key Answer

For a standard 4,000 PSI concrete mix (1:2:3 volume ratio), one cubic yard of concrete requires six (6) 94-lb bags of Portland cement, roughly 1,400 lbs (0.7 tons) of washed sand, 1,900 lbs (0.95 tons) of 3/4" gravel, and approximately 32 gallons of clean water.

A 94-lb bag of Type I/II Portland cement equals exactly 1 cubic foot.
Water-cement ratio should not exceed 0.45 for freeze-thaw durable concrete.
Curing concrete moist for 7 days doubles its early compressive strength.

Interactive Calculator

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Total Concrete Volume Neededcubic yards

cubic yards

Target Compressive Strength

Calculated OutputBatch Recipe Calculated

Portland Cement (94-lb Bags)

6 Bags

Washed Concrete Sand: 0.70 tons (1,400 lbs)
Crushed Stone / Gravel (3/4"): 0.95 tons (1,900 lbs)
Mixing Water Needed: 32 Gallons
Water-Cement Ratio (w/c): 0.45

Note: Strictly adhere to the water-cement ratio. Adding excess water weakens cured concrete compressive strength dramatically.

The Critical Water-Cement Ratio

Every gallon of excess water added to make concrete easier to pour cuts compressive strength by roughly 200 PSI.

Frequently Asked Questions

Common questions regarding this calculation and code compliance

1 part Portland cement, 2 parts clean sand, and 3 parts gravel/crushed stone by loose volume.