Concrete Mix Ratio: Cement, Sand, Gravel, and Water

Concrete mix ratio describes how much cement, sand, and coarse aggregate go into a batch. The classic all-purpose recipe is 1 part cement, 2 parts sand, and 3 parts gravel by volume, often written as 1:2:3. Add just enough clean water to make it workable. Ratios shift for stronger or leaner mixes, and the amount of water matters as much as the dry ingredients.

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Common mix ratios

Ratio (cement:sand:gravel)	Typical use	Rough strength range
1:1.5:3	Stronger slabs, structural work	Higher, roughly 3,500 to 4,000+ psi
1:2:3	General purpose slabs, walks, footings	Moderate, roughly 3,000 psi
1:2:4	Footings, post holes, mass fill	Moderate to lower
1:3:6	Lean fill, blinding layers	Low

Strength ranges are rough because real strength depends on materials, water, mixing, and curing. For anything structural, use ready-mix or bagged concrete rated to a specific psi.

Water is the key variable

The water-cement ratio is the weight of water divided by the weight of cement. Lower ratios make stronger, more durable concrete, while extra water makes it easier to place but weaker and more prone to cracking and scaling. Many outdoor mixes target a water-cement ratio around 0.45 to 0.50. In practice, add water gradually until the mix holds its shape like thick oatmeal and is not soupy.

Volume vs weight

Volume ratios are convenient with buckets or shovels but less precise, because sand bulks up when damp. Plants batch by weight for consistency. If you mix by the bucket:

Use the same bucket for every ingredient.
Keep sand covered so moisture is consistent.
Mix the dry materials first, then add water.

How much material per batch

As a rough guide, a 1:2:3 mix made with one 94-pound bag of portland cement yields somewhere around 4.5 cubic feet of concrete, depending on materials. For small jobs, premixed bags are simpler: an 80-pound bag typically yields about 0.6 cubic feet. Our guide to bags of concrete in a yard covers bag counts.

When to mix your own

Small jobs under about a cubic yard, such as fence posts or small pads.
Remote spots a truck cannot reach.
Repair work in small quantities.

For slabs over a yard or two, ready-mix usually costs less in time and gives more consistent strength. See concrete cost per yard for pricing factors.

Tips for better homemade concrete

Use clean, well-graded sand and gravel, not dirty fill.
Mix thoroughly so every stone is coated.
Place concrete within about an hour or two of mixing, sooner in hot weather.
Keep it moist while it cures.

Bottom line

The standard concrete mix ratio is 1:2:3 cement, sand, and gravel by volume, with just enough water to make it workable. Go richer for stronger work and leaner for fill, keep water to a minimum, and switch to ready-mix for larger pours. Estimate the volume first with the concrete calculator.

Questions people ask

What is the standard concrete mix ratio?

About 1 part cement, 2 parts sand, and 3 parts gravel by volume, with water added to a workable consistency.

What is a good water-cement ratio?

Many outdoor mixes target about 0.45 to 0.50 by weight. Less water generally means stronger concrete.

What ratio is used for footings?

Footings often use a 1:2:3 or 1:2:4 mix, but follow local code and plans for structural work.

How much concrete does one bag of cement make?

With a 1:2:3 mix, a 94-pound bag of portland cement makes roughly 4.5 cubic feet of concrete.

Is mixing my own concrete cheaper?

For small jobs it can be. For larger slabs, ready-mix usually saves time and gives more consistent strength.

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