Quick answer
Dry volume = wet volume × dry-to-wet factor × (1 + waste), then each material is its share of the mix. One cubic yard of 1:2:4 concrete with a 1.54 factor and 5% waste needs 6.24 bags (94 lb) of cement, 12.47 ft³ of sand and 24.95 ft³ of coarse aggregate.
Enter the concrete volume, the nominal mix, the dry-to-wet factor and the waste allowance. The calculator returns cement, sand and aggregate.
Related tools: Concrete Weight Calculator: Weight of a volume of concrete from its density. Concrete Steps Calculator: Concrete volume for solid stacked steps. Concrete Volume Calculator: Cubic yards of concrete and bags needed for a slab, footing or pad.
How to use the Concrete Mix Calculator
- Enter volume of concrete (0.001 or more).
- Choose volume unit: Cubic yards, Cubic metres and Cubic feet.
- Choose nominal mix (cement : sand : aggregate): 1 : 1.5 : 3, 1 : 2 : 4 and 1 : 3 : 6.
- Enter dry-to-wet volume factor (between 1.2 and 1.8). It starts at 1.54.
- Enter allowance for waste (%) (between 0 and 50). It starts at 5.
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Volume of concrete | A number | ≥ 0.001 |
| Volume unit | Choose one: Cubic yards; Cubic metres; Cubic feet | Starts at Cubic yards |
| Nominal mix (cement : sand : aggregate) | Choose one: 1 : 1.5 : 3; 1 : 2 : 4; 1 : 3 : 6 | Starts at 1 : 2 : 4 |
| Dry-to-wet volume factor | A number | ≥ 1.2, ≤ 1.8, starts at 1.54 |
| Allowance for waste (%) | A number | ≥ 0, ≤ 50, starts at 5 |
Formula and method
Formula
dry volume = wet volume × factor × (1 + waste); each material = dry volume × its share of the mix; 94-lb bag of cement = 1 ft³
IEEE-754 double precision; shown to at most 6 decimal places.
Classic nominal-mix estimate by volume: loose dry materials occupy about 1.54 times the volume of the wet concrete they make (the voids fill when mixed), so the dry volume is split in the mix ratio. In US practice a 94-lb bag of Portland cement is counted as 1 cubic foot of loose cement. This estimates quantities only; it is not a mix design (water-cement ratio, strength, air entrainment and admixtures need a proper design to ACI 211 or local codes), and ready-mix or bagged mixes list their own yields. Add the water your supplier's instructions specify.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Volume of concrete = 1; Volume unit = Cubic yards; Nominal mix (cement : sand : aggregate) = 1 : 2 : 4; Dry-to-wet volume factor = 1.54; Allowance for waste (%) = 5.
| Result | Value |
|---|---|
| Cement | 6.24 bags (94 lb) |
| Cement weight | 586 lb |
| Sand | 12.47 ft³ (0.46 yd³) |
| Coarse aggregate | 24.95 ft³ (0.92 yd³) |
| Total dry volume | 43.66 ft³ |
| Wet volume of concrete | 27 ft³ |
Example 2
Inputs: Volume of concrete = 2.5; Volume unit = Cubic metres; Nominal mix (cement : sand : aggregate) = 1 : 1.5 : 3; Dry-to-wet volume factor = 1.54; Allowance for waste (%) = 10.
| Result | Value |
|---|---|
| Cement | 27.19 bags (94 lb) |
| Cement weight | 2,556 lb |
| Sand | 40.79 ft³ (1.51 yd³) |
| Coarse aggregate | 81.58 ft³ (3.02 yd³) |
| Total dry volume | 149.56 ft³ |
| Wet volume of concrete | 88.29 ft³ |
Example 3
Inputs: Volume of concrete = 40; Volume unit = Cubic feet; Nominal mix (cement : sand : aggregate) = 1 : 3 : 6; Dry-to-wet volume factor = 1.5; Allowance for waste (%) = 0.
| Result | Value |
|---|---|
| Cement | 6 bags (94 lb) |
| Cement weight | 564 lb |
| Sand | 18 ft³ (0.67 yd³) |
| Coarse aggregate | 36 ft³ (1.33 yd³) |
| Total dry volume | 60 ft³ |
| Wet volume of concrete | 40 ft³ |
The first line is the headline result (cement). Below it the concrete Mix Calculator lists cement weight, sand, coarse aggregate, total dry volume and wet volume of concrete, which describe the same case from other angles. IEEE-754 double precision; shown to at most 6 decimal places.
The 1:2:4 mix
The parts add to 7. One cubic yard is 27 ft³ wet; dry materials are 27 × 1.54 = 41.58 ft³, and with 5% waste 43.66 ft³. Cement is 1/7 of that, 6.24 ft³ (one 94 lb bag is about 1 ft³).
An estimate of materials
This is a volumetric estimate only. Strength depends on the water-cement ratio, aggregate grading and curing, and the dry-to-wet factor varies with the aggregates. For structural work use an engineered mix design or ready-mix.
How the result changes with volume of concrete
Holding every other input at the first worked example, this table changes only volume of concrete. It shows how sensitive the answer is to that one value; each row was produced by running this calculator.
| Volume of concrete | Cement | Cement weight | Sand |
|---|---|---|---|
| 0.5 | 3.12 bags (94 lb) | 293 lb | 6.24 ft³ (0.23 yd³) |
| 1 | 6.24 bags (94 lb) | 586 lb | 12.47 ft³ (0.46 yd³) |
| 2 | 12.47 bags (94 lb) | 1,173 lb | 24.95 ft³ (0.92 yd³) |
| 4 | 24.95 bags (94 lb) | 2,345 lb | 49.9 ft³ (1.85 yd³) |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Volume of concrete: left empty shows "Enter volume of concrete." beside that field and no result.
- Dry-to-wet volume factor: entering "1.0" shows "Dry-to-wet volume factor must be at least 1.2." beside that field and no result.
Choosing between the Concrete Mix Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Concrete Weight Calculator](/construction/concrete-weight-calculator/) | volume, volume unit and density | Weight |
| [Concrete Steps Calculator](/construction/concrete-steps-calculator/) | number of steps, riser height and tread depth | Concrete volume |
| [Concrete Volume Calculator](/construction/concrete-volume-calculator/) | length, width and thickness | Concrete needed |
| [Post Hole Concrete Calculator](/construction/post-hole-concrete-calculator/) | hole diameter, hole depth and post shape | Concrete per hole |
| [Concrete Block Fill Calculator](/construction/concrete-block-fill-calculator/) | blocks with filled cores, core volume per block and waste allowance | Fill needed |
Background: construction estimates
Material quantities are geometry plus a margin. Calculate the exact volume or area, add an allowance for waste, spillage, cuts and uneven ground (calculator pages commonly mention 5 to 10 percent, a rule of thumb that varies by material and job) and round up to whole units. One cubic yard is exactly 27 cubic feet.
Suppliers often have minimum order sizes and may charge for small loads, so confirm quantities, product yields and local code with your supplier or a qualified estimator before ordering.
Assumptions and limitations
- Volumetric estimate of materials only
- The dry-to-wet factor varies with aggregate grading
Quantities are estimates. Add allowances for waste and site conditions, and follow local codes and a qualified professional's instructions for structural or safety-critical work.
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for volume of concrete and dry-to-wet volume factor to confirm this.
Frequently asked questions
What does 1:2:4 mean?
One part cement, two parts sand, four parts aggregate by volume.
How much water?
Enough for workability, typically a water-cement ratio near 0.5.
Is bagged mix easier?
For small jobs, yes.
What does the Concrete Mix Calculator calculate?
Cement, sand and aggregate for a nominal volume mix such as 1:2:4. It returns Cement, Cement weight, Sand, Coarse aggregate and Total dry volume.
What formula does the Concrete Mix Calculator use?
dry volume = wet volume × factor × (1 + waste); each material = dry volume × its share of the mix; 94-lb bag of cement = 1 ft³. Classic nominal-mix estimate by volume: loose dry materials occupy about 1.54 times the volume of the wet concrete they make (the voids fill when mixed), so the dry volume is split in the mix ratio.
What do I need to enter in the concrete Mix Calculator?
You enter Volume of concrete, Volume unit, Nominal mix (cement : sand : aggregate), Dry-to-wet volume factor and Allowance for waste (%).
How is the result rounded or limited?
IEEE-754 double precision; shown to at most 6 decimal places. Volumetric estimate of materials only.
What are the limits of this calculator?
Volumetric estimate of materials only. The dry-to-wet factor varies with aggregate grading.
What does the “Volume unit” option change?
It sets how the concrete Mix is worked out. The choices are Cubic yards, Cubic metres and Cubic feet.
What is an example of a concrete Mix result?
With volume of concrete 1, volume unit Cubic yards, nominal mix (cement : sand : aggregate) 1 : 2 : 4, dry-to-wet volume factor 1.54 and allowance for waste (%) 5, the cement is 6.24 bags (94 lb).
Where does the method come from?
The method follows: Nominal volumetric proportioning of concrete (dry-volume factor 1.52 to 1.57; 1.54 is the commonly used value); Portland Cement Association convention: a 94-lb bag of Portland cement is taken as 1 cubic foot of loose volume; ACI 211.1 for engineered mix design (not implemented here).
Can I rely on this calculator for a decision?
Quantities are estimates. Add allowances for waste and site conditions, and follow local codes and a qualified professional's instructions for structural or safety-critical work. For this calculator in particular: Volumetric estimate of materials only.
Related calculators
- Concrete Weight Calculator — Weight of a volume of concrete from its density.
- Concrete Steps Calculator — Concrete volume for solid stacked steps.
- Concrete Volume Calculator — Cubic yards of concrete and bags needed for a slab, footing or pad.
- Post Hole Concrete Calculator — Concrete per post hole after the post's volume.
- Concrete Block Fill Calculator — Grout or concrete needed to fill block cores.
- Concrete Reinforcing Mesh Calculator — Mesh sheets for a slab, allowing for overlaps.
- Concrete Block Calculator — Concrete blocks and mortar volume for a wall.
- Sonotube Calculator — Concrete volume and bags for round column forms.
Sources
- Nominal volumetric proportioning of concrete (dry-volume factor 1.52 to 1.57; 1.54 is the commonly used value)
- Portland Cement Association convention: a 94-lb bag of Portland cement is taken as 1 cubic foot of loose volume
- ACI 211.1 for engineered mix design (not implemented here)
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.