Concrete Mix Calculator

A concrete mix calculator returns the portland cement bags, sand and gravel needed to hand-batch a target volume of concrete at a 1:2:3 ratio. It starts from 5.5 bags of cement per cubic yard by default, adds 5% waste, and rounds sand and gravel up to the nearest quarter cubic yard.

Last reviewed September 2026Method & sources Report an error

Portland Cement (94 lb bags)

Includes a 5% waste allowance.

Shopping list

Portland cement6 94 lb bags
Sand0.5 cu yd
Bagged
Gravel0.75 cu yd
Bagged

Breakdown
Portland Cement (94 lb bags)	6
Sand	0.50 cu yd
Gravel	0.75 cu yd
Estimated Cost (Cement)
Estimated Cost (Sand)
Estimated Cost (Gravel)

How to Calculate Concrete Mix

This calculator splits a target concrete volume into raw ingredients rather than a bagged premix. It's for anyone batching from separate cement, sand, and gravel. QUIKRETE's Portland Cement data sheet lists 1 part cement, 2 parts sand, and 3 parts gravel (by volume) as its typical concrete mix design. It states that 5 to 6 94 lb bags of cement are used per cubic yard of finished concrete. This calculator lets you pick a lean (5), standard (5.5), or rich (6) mix within that stated range, since more cement generally means higher strength at higher cost. Sand and gravel are then scaled directly off the cement figure using the 1:2:3 ratio. That scaling relies on the long-standing construction convention that a 94 lb bag of portland cement occupies roughly 1 cubic foot of loose volume. That convention is what makes the ratio and the bags-per-yard figure consistent with each other. A waste allowance is applied to the target volume before any of this math runs. Sand and gravel are rounded up to the nearest 1/4 cubic yard, matching how bulk aggregate is typically ordered.

Example: 1 cubic yard of concrete, standard mix (5.5 bags/cu yd), at 5% waste

1 cubic yard of concrete, standard mix (5.5 bags/cu yd), at 5% waste: 1. Raw volume: 1 cu yd × 27 = 27 cu ft 2. With 5% waste: 27 × 1.05 = 28.35 cu ft = 1.05 cu yd 3. Raw cement bags: 1.05 × 5.5 = 5.775, rounded up to 6 bags 4. Sand (2 parts, using the raw 5.775-bag figure): 5.775 × 2 = 11.55 cu ft = 0.428 cu yd, rounded up to 0.50 cu yd 5. Gravel (3 parts): 5.775 × 3 = 17.325 cu ft = 0.642 cu yd, rounded up to 0.75 cu yd That's 6 bags of cement, 1/2 cu yd of sand, and 3/4 cu yd of gravel to batch about 1 cubic yard of concrete at a standard mix.

Concrete Mix: Compare Scenarios

Scenario	Portland Cement (94 lb bags)	Sand	Gravel
Small (0.5 cu yd patch)	3	0.25 cu yd	0.50 cu yd
Medium (1 cu yd, standard mix)	6	0.50 cu yd	0.75 cu yd
Large (5 cu yd footing pour)	29	2.25 cu yd	3.25 cu yd

What Is Concrete Mix?

A concrete mix calculator breaks a target volume of concrete down into the raw materials needed to batch it yourself: portland cement, sand, and gravel. It's the alternative to buying a bagged, pre-blended concrete mix. It's the right tool when cement, sand, and gravel are being sourced separately. That's common on a larger DIY pour, where separate bulk materials cost less than dozens of pre-mixed bags. It isn't the right tool when a single bag of Quikrete- or Sakrete-style concrete mix is being used. For that, see the Concrete Slab calculator.

Concrete Mix: Pros and Cons

Pros

Uses QUIKRETE's own published 1:2:3 mix design and bags-per-yard range instead of an unsourced ratio
Lets sand and gravel track a fractional cement figure before rounding, so the ratio between the three materials stays accurate even after the cement count rounds up to a whole bag
Rounds bulk aggregate to the quarter-yard increments a supplier actually sells, not a raw decimal

Cons

Doesn't specify water quantity. Water content depends on desired slump/workability and moisture already in the sand. It's normally added to the mix's needed consistency rather than a fixed ratio, so it's outside this calculator's scope
The 94 lb bag ≈ 1 cubic foot figure is a long-standing construction convention, not a precise physical constant. Actual loose bulk density varies somewhat by cement brand and how settled the bag is
Assumes a general-purpose 1:2:3 mix. A structural mix design with a specific target PSI and water-cement ratio should come from an engineer or a lab mix design, not a volumetric rule of thumb

Concrete Mix: What a Pro Checks

Add water gradually while mixing until it holds its shape on a trowel without being stiff or crumbly. This calculator doesn't set a water quantity, since the right amount depends on your sand's existing moisture and the workability you need.
Pick a mix richness to match the job, not habit. QUIKRETE's own data sheet lists 5 to 6 94 lb bags per cubic yard for a standard 1:2:3 mix. The lower end is more economical and the higher end is generally stronger.
Treat the 94 lb-bag-equals-1-cubic-foot figure as a planning convention, not a lab measurement. Actual loose bulk density varies a bit by cement brand, so a large order is worth double-checking against your supplier's own numbers.

Frequently Asked Questions

What is the 1:2:3 concrete mix ratio?

1 part portland cement, 2 parts sand, and 3 parts gravel, measured by volume (not weight). It's QUIKRETE's own published typical mix design for general-purpose concrete, and one of the most common ratios used for DIY batching from raw materials rather than a pre-blended bag.

How many bags of cement are in a cubic yard of concrete?

About 5 to 6 94 lb bags for a standard 1:2:3 mix, per QUIKRETE's Portland Cement data sheet. Use 5 for a leaner, more economical mix, or 6 for a richer, generally stronger one. This calculator lets you pick within that range.

Is a 94 lb bag of cement really 1 cubic foot?

Approximately, yes. It's the long-standing construction-industry convention behind the 1:2:3-by-volume rule, though actual loose bulk density varies slightly by brand and how settled the bag is. It isn't an exact physical constant, but it's accurate enough for material estimating at this scale.

How much water do I add?

This calculator doesn't specify a water amount. The right quantity depends on the desired workability (slump) and how much moisture is already in your sand, and too much water weakens the cured concrete. Add water gradually while mixing until the mix holds its shape on a trowel without being stiff or crumbly, per standard concrete-mixing practice.

What's the difference between this and the Concrete Slab calculator?

The Concrete Slab calculator assumes you're buying a bagged, pre-blended concrete mix (cement, sand, and gravel already combined in one bag) or ordering ready-mix by the truck. This calculator is for batching from separate cement, sand, and gravel. It's typically more cost-effective on a larger pour, but it takes more equipment and labor to mix correctly.

Can I use a different ratio, like 1:2:4?

This calculator is built around the 1:2:3 ratio QUIKRETE publishes, since that's the one with a citable bags-per-yard figure behind it. A leaner ratio like 1:2:4 uses proportionally less cement per unit of aggregate and is common for less critical fill or mass concrete. If your project specifies a different ratio, scale the sand and gravel figures here proportionally, or consult your project's mix design.

Sources

QUIKRETE Portland Cement No. 1124 Data Sheet (1:2:3 typical concrete mix design; 5-6 bags per cubic yard) (opens in a new tab)

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