Standard Concrete Mix Ratio

Quick answer

Standard Concrete Mix Ratio: 1:2:4 = 1 cement : 2 sand : 4 stone by volume. Dry volume ≈ wet × 1.54 to cover voids in loose aggregate. A ratio is not a psi rating — order 3,000 psi or 25 MPa from the plant when the drawing says so.

Standard Concrete Mix Ratio: Reading the three numbers

Same bucket each time. 1:3:6 is leaner (more aggregate per cement). 1:1.5:3 and 1:1:2 are richer. Site batching by shovel is only as good as consistent parts — use the same container.

Standard Concrete Mix Ratio: Why 1.54 shows up

Loose sand and stone have voids. The 1.54 factor is a common rule for converting wet concrete volume into dry material volume on nominal site mixes. It is a convention, not a lab mix design. Ready-mix plants do not batch your patio with a 1.54 chalkboard factor — they use weighed mix designs.

When not to use a ratio

If the drawing says 3,000 psi, 4,000 psi, or 25 MPa, order that from the plant. Structural, public, and engineered residential work belongs on a ticket, not a blog ratio. Use ratios for small site mixes when a ratio was actually specified or you accept the limits.

Water

About 5–6 gallons per 94 lb cement bag is a starting range. Workability comes from water and aggregate moisture. More water than needed cuts strength. Follow a plant mix or a known bagged product when strength matters.

Do it in Concrete Calculator

Get wet yards from any shape calculator, then open the mix ratio calculator. For a full 1:2:4 yard breakdown see the 1:2:4 mix guide.

Common nominal ratios compared

1:3:6 lean mass fill uses less cement per yard. 1:2:4 is a common general nominal mix in teaching examples. 1:1.5:3 and 1:1:2 spend more cement for richer pastes. None of these lines equal a stamped psi grade without testing and control.

If you came from a “concrete mix ratio” search wanting bags of cement, run the mix ratio calculator after you know wet yards. If you wanted a truck with a strength, call the plant with the psi or MPa from the drawing.

Classroom ratios vs bags of premix

Bagged concrete mix is already proportioned. You do not apply 1:2:4 on top of a Quikrete bag. Ratios are for bulk cement, sand, and stone. Premix bags are for small pours where the manufacturer already chose the blend.