Cement Quantity Calculator

Enter your concrete volume and mix ratio to instantly calculate how much cement you need in bags, pounds, and kilograms — with proportions for sand and aggregate.

Free to use No sign-up required Based on ACI 211 mix design Imperial & metric supported

✓ Bags (47 lb, 94 lb) ✓ Weight in lb & kg ✓ Sand & aggregate proportions ✓ Last verified May 2026

Reviewed by the AllConcreteCalculator.com editorial team — formulas cross-checked against ACI 211 mix design standards, May 2026.

Enter Your Concrete Volume & Mix Ratio

Concrete Volume

The total concrete volume you need to fill. Use our Slab Calculator first if you don't know this number. Please enter a valid volume greater than 0.

Mix Design Select a standard mix or enter a custom C:S:A ratio below.

Mix Ratio (Cement : Sand : Aggregate)

: :

Cement Sand Aggregate

Waste / Overage Factor (%)

Add 5% for standard batches. Increase to 10% for hand-mixing or first-time pours.

Cement Bulk Density (optional)

US standard bag = 94 lb/ft³. Leave as-is unless your supplier specifies otherwise.

Price per 94 lb Bag (optional)

Leave blank to skip cost estimate. US average: $12–$18 per 94 lb bag.

Results appear instantly. No sign-up required.

Your Cement Estimate

Cement Required (includes waste)

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Pounds (lb)

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Kilograms (kg)

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Cubic Feet (ft³)

Bags Required (includes waste)

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47 lb bags

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94 lb bags

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50 kg bags

— Sand (lb)

— Aggregate (lb)

— Mix Ratio C:S:A

— Waste Factor

Estimated Cement Cost

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Cement material cost only. Sand, aggregate, water, admixtures, labor, and delivery are additional. Use our Full Project Estimator for a complete breakdown.

Step 1: Convert volume to cubic feet (1 yd³ = 27 ft³; 1 m³ = 35.3147 ft³)
Step 2: Total ratio parts = C + S + A (e.g. 1+2+4 = 7)
Step 3: Dry volume factor = 1.54 (concrete shrinks ~35% from dry mix to wet set)
Step 4: Dry volume (ft³) = Concrete volume (ft³) × 1.54
Step 5: Cement volume (ft³) = Dry volume × C ÷ (C+S+A)
Step 6: Cement weight (lb) = Cement volume (ft³) × density (lb/ft³)
Step 7: Final weight = Cement weight × (1 + waste% ÷ 100)
Step 8: 94 lb bags = CEIL(Final weight ÷ 94) — never round down
Sand lb = Dry volume × S ÷ (C+S+A) × 100 lb/ft³ × waste factor
Aggregate lb = Dry volume × A ÷ (C+S+A) × 100 lb/ft³ × waste factor

How to Use This Cement Quantity Calculator

Find your total concrete volume first. This calculator works on finished concrete volume — the space you're filling, not the raw materials. If you haven't calculated volume yet, use the Concrete Slab, Footing, or Column calculators on this site first. Enter the cubic yards, cubic feet, or cubic meters from that result directly here.
Select your mix design or enter a custom ratio. Choose from the preset mix options based on your required PSI strength. The 1:2:4 standard mix covers most residential flatwork and foundations at 3,000–3,500 PSI. For slabs that will take vehicle loads or freeze-thaw cycles, use 1:1.5:3 or stronger. If your engineer or ready-mix supplier has specified a custom C:S:A ratio, enter it directly in the ratio fields.
Add a waste factor. Hand-mixing is imprecise. Spillage, bag remnants, and variation in mixing bowls all eat into your yield. A 5% waste factor is the minimum for competent mixing. Jump to 10% if you're mixing by hand in a wheelbarrow, working on a large pour, or using an older mixer with dead zones. Never reduce to 0% — it's physically impossible to use every gram from a bag.
Use the results to order bags and weigh dry materials. The 94 lb bag count is the number you buy at a supplier. The pound and kilogram figures are what you'd weigh out if batching by weight (more accurate than volume scooping). The sand and aggregate pounds in the summary row give you the full dry-batch quantities for a complete material order.

⚠ Pro Tip: Always apply the 1.54 dry volume factor before calculating cement. Dry mixed materials compact and trap air gaps. When water is added and hydration occurs, the concrete shrinks to roughly 65% of the original dry volume. Skipping this factor leaves you 35% short on materials — the single most common mix design error on jobsites.

Cement Quantity Formula

The calculation uses the volumetric proportioning method aligned with ACI 211 mix design guidelines. The critical factor is the dry volume multiplier of 1.54, which accounts for the void space in dry aggregates that disappears during hydration.

Step	Formula	Example (1 yd³, 1:2:4 mix)
1. Convert to cubic feet	1 yd³ × 27	27 ft³
2. Apply dry volume factor	27 × 1.54	41.58 ft³ dry
3. Total ratio parts	1 + 2 + 4	7 parts
4. Cement fraction (ft³)	41.58 × 1/7	5.94 ft³
5. Cement weight (lb)	5.94 × 94 lb/ft³	558.4 lb
6. Add 5% waste	558.4 × 1.05	586.3 lb
7. 94 lb bags	CEIL(586.3 ÷ 94)	7 bags

Cement Quantity Reference Table

Cement required per cubic yard at common mix ratios — no waste factor applied. Add 5–10% for real-world batching.
Mix Ratio (C:S:A)	Cement (lb/yd³)	94 lb Bags / yd³	50 kg Bags / yd³	Approx. PSI
1:1:2	1,053 lb	12 bags	11 bags	5,000+
1:1.5:3	793 lb	9 bags	8 bags	4,000
1:2:3	703 lb	8 bags	7 bags	3,500
1:2:4	558 lb	6 bags	6 bags	3,000–3,500
1:3:5	431 lb	5 bags	4 bags	2,500
1:3:6	376 lb	4 bags	4 bags	2,000

Values use 94 lb/ft³ cement density and 1.54 dry volume factor. Add waste before ordering.

Which Concrete Mix Ratio Do I Need?

The mix ratio determines the strength, workability, and durability of your finished concrete. Cement is the expensive binder — more cement means higher strength but also higher cost and more heat of hydration. Use the minimum cement content that meets your structural requirements.

Recommended mix ratios by application type and required compressive strength.
Application	Mix Ratio (C:S:A)	Min. PSI	Notes
Sidewalks, footpaths	1:2:4	3,000	Standard residential use
Residential slabs, patios	1:2:4	3,000	Add 10% in freeze-thaw zones
Driveways (residential)	1:2:3	3,500	Cars and light trucks
Garage floors	1:2:3	3,500	Rebar recommended
Foundations, footings	1:1.5:3	4,000	Structural loads
Columns, beams	1:1.5:3	4,000	Engineer design required
High-strength structural	1:1:2	5,000+	Low w/c ratio, superplasticizer often used
Mass fill, blinding layer	1:3:6	2,000	Non-structural use only

Ratios specify volumetric proportions by weight (or by loose volume on smaller jobs). On critical structural work, batching by weight using a scale is far more accurate than scooping by bucket. A 10% variation in cement content from sloppy volume batching can cost you several hundred PSI in final strength.

Common Mistakes When Calculating Cement Quantity

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Skipping the 1.54 dry volume factor. This is the most expensive mistake. Dry cement, sand, and aggregate have voids between particles. When mixed with water, those voids collapse and the concrete compacts. If you calculate cement for 1 yd³ without the 1.54 multiplier, you'll produce only about 0.65 yd³ of finished concrete. You need roughly 54% more dry material than the finished volume suggests.
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Confusing concrete volume with cement volume. Cement is one ingredient in concrete — not the whole thing. A 1:2:4 mix has 7 total parts, so cement is only 1/7 of the dry volume. Using the full concrete volume as the cement quantity gives you 7x too much. Every part of this calculation is about proportioning correctly, not ordering the entire volume in bags.
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Ignoring the water-cement ratio. The mix ratio (C:S:A) determines aggregate proportions but says nothing about water content. The water-cement (w/c) ratio controls strength and durability independently. Typical w/c ratios range from 0.40 to 0.60. Adding too much water to make the mix easier to work with weakens the concrete far more than most contractors realize — every 0.05 increase in w/c ratio costs approximately 500 PSI in compressive strength.
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Assuming all cement bags are the same size. In the US, the standard Portland cement bag is 94 lb (1 cubic foot). But 47 lb half-bags exist, and international projects use 50 kg bags (110 lb). Premix bags (like Quikrete or Sakrete) come in 40, 60, and 80 lb sizes but include sand and aggregate already — they are not pure cement. Ordering the wrong bag size leaves you with a stack of bags that don't add up to the quantity needed.
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Ordering exactly the number of bags calculated with no buffer. Bag remnants, spillage, and mixer dead zones mean you will never extract 100% of the cement from every bag. A 5% waste factor is the minimum. On-site mixing with variable water additions can further affect yield. Short by even one bag mid-pour and you either have to wait for a hardware run or produce a cold joint.

Frequently Asked Questions

First, find your total concrete volume in cubic feet. Multiply by 1.54 to get the dry volume (accounts for compaction during hydration). Divide by the total ratio parts (cement + sand + aggregate). Then multiply by the cement fraction to get cement volume in cubic feet. Multiply by the cement density (94 lb/ft³ for standard Portland) to get the weight in pounds. Finally, divide by 94 to get the number of 94 lb bags and always round up — never round down. This calculator does all of that in one step.
When you mix dry aggregates together, there are air voids between particles. When water is added and cement hydrates, those voids fill in and the volume shrinks. Dry concrete ingredients occupy roughly 54% more volume than the finished wet concrete. The 1.54 multiplier compensates for this: if you need 1 cubic foot of finished concrete, you need 1.54 cubic feet of dry materials. Without this factor, every mix calculation underestimates cement and aggregate quantities by about 35%.
Cement is one ingredient in concrete — the fine grey powder (typically Portland cement) that acts as a binder. Concrete is the finished material made by mixing cement, sand, coarse aggregate (gravel or crushed stone), and water. You cannot pour cement alone and get a structural result. Ordering "a yard of cement" from a ready-mix plant is a common mistake — they sell concrete, not raw cement. Cement is what you buy in bags when hand-mixing or self-batching.
It depends entirely on your mix ratio. A standard 1:2:4 mix requires approximately 6 bags of 94 lb Portland cement per cubic yard of finished concrete (before waste). A stronger 1:1.5:3 mix needs about 9 bags per cubic yard. A lean 1:3:6 fill mix uses roughly 4 bags per cubic yard. The rule of thumb of "6 bags per yard" applies specifically to a 1:2:4 mix at 3,000 PSI — it does not apply to other mix designs.
A 1:2:4 mix (1 part cement : 2 parts sand : 4 parts aggregate by volume) with a water-cement ratio of around 0.50–0.55 produces approximately 3,000–3,500 PSI at 28 days. This is the standard specification for residential sidewalks, patios, and ground-floor slabs. Note that the actual strength depends heavily on the w/c ratio, aggregate quality, curing conditions, and cement grade — the mix ratio is only part of the equation. In freeze-thaw climates, add air entrainment for durability regardless of PSI target.
Weight batching is significantly more accurate than volume batching and is required by ACI 301 for structural concrete. Dry aggregates vary in bulk density depending on moisture content, gradation, and how tightly they're packed into a bucket. A "1 part sand" scoop can vary by 10–15% from batch to batch depending on how wet or dry the sand is. Weight batching eliminates this variability. For large or structural pours, invest in a simple contractor scale. For small DIY jobs, volume batching with consistent same-sized buckets is acceptable.
Portland cement (Type I/II) is the standard general-purpose cement used in most concrete construction. It comes in a standard 94 lb bag in the US. Alternatives include Type III (rapid hardening, for cold weather or fast-form stripping), blended cements like Portland-slag (Type IS) or Portland-fly ash (Type IP) which reduce carbon footprint and improve long-term strength, and masonry cements for mortar applications. For most residential concrete work, Type I/II is appropriate. High-sulfate soils require Type V. This calculator assumes standard Portland cement at 94 lb/ft³ density.
Yes — premix bags (Quikrete 5000, Sakrete High Strength, etc.) already contain the correct proportions of cement, sand, and aggregate. You just add water. This calculator is for scenarios where you're sourcing cement, sand, and aggregate separately — either because premix is too expensive for large pours, or because you need a specific non-standard mix ratio. For jobs under about 0.5 cubic yards, premix bags are often more practical. For anything larger, buying ingredients separately and batching to a specified mix ratio is significantly cheaper per cubic yard.
Unopened Portland cement bags stored in a dry, well-ventilated location typically remain usable for 3 months from the manufacture date. In humid climates or uncontrolled storage, this drops to 4–6 weeks before the cement starts to absorb atmospheric moisture and pre-hydrate. Pre-hydrated cement produces lumps, reduced strength, and inconsistent batching. Always check bags for hard lumps before use — if you can break them by hand, the cement is likely still usable. If lumps won't crush, the material has partially set and should be discarded.
For a standard 1:2:4 residential mix, use coarse aggregate with a maximum nominal size of 3/4 inch (19 mm). This is the most widely available specification and provides good workability without segregation. For thin slabs under 4 inches thick, limit aggregate to 3/8 inch maximum to avoid bridging. For mass concrete (foundations, footings over 12 inches thick), you can increase to 1.5 inch aggregate to reduce cement demand and heat of hydration. ACI 318 specifies that maximum aggregate size should not exceed 1/5 of the narrowest form dimension or 3/4 of the minimum rebar clear spacing.