Concrete Admixture Dosage Calculator

Enter your concrete volume, admixture type, and dosage rate to instantly calculate total admixture needed in fluid ounces, liters, and mL per 100 kg of cement.

Free to use No sign-up required ASTM C494 / ASTM C260 aligned Imperial & metric supported

✓ oz/yd³ and mL/100kg outputs ✓ Total quantity in fl oz & liters ✓ 6 admixture types covered ✓ Last verified May 2026

Reviewed by the AllConcreteCalculator.com editorial team — dosage formulas cross-checked against ASTM C494, ASTM C260, and manufacturer technical data sheets, May 2026.

Enter Your Batch & Admixture Details

Admixture Type

Choose the admixture class — typical dosage ranges will auto-populate as a reference.

Concrete Volume

Total concrete batch or pour volume. Please enter a valid volume greater than 0.

Dosage Rate

From the product TDS. Typical range shown below for selected type. Please enter a valid dosage rate greater than 0.

Cement Content (required for mL/100 kg)

Cementitious content of the mix design. Typical range: 470–800 lb/yd³ (280–475 kg/m³). Cement content is required when dosage is entered as mL/100 kg.

Overage Factor (%)

Add 5% buffer for spillage, residue in dispensing lines, and measurement error.

Typical dosage range for selected type: Select a type above to see typical rates.

Quick-fill typical dosage:

Admixture Cost per Gallon (optional)

Leave blank to skip cost estimate. Typical range: $8–$60/gal depending on type.

Results appear instantly. No sign-up required.

Your Admixture Estimate

Total Admixture Required (with overage)

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Fluid Ounces (fl oz)

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Liters (L)

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US Gallons

Equivalent Dosage Expressions

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fl oz / yd³

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mL / 100 kg cement

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mL / L of concrete

— Concrete Volume

— Dosage Rate

— Admixture Type

— Overage Factor

Estimated Admixture Material Cost

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Admixture material cost only, based on price per gallon entered. Labor, dispensing equipment, and waste disposal not included. Confirm pricing with your admixture supplier — prices vary by region and order volume.

Step 1: Convert volume to cubic yards (1 m³ = 1.308 yd³; 1 ft³ = 0.03704 yd³)
Step 2: Convert dosage to fl oz / yd³
  • If entered as fl oz/yd³: use directly
  • If entered as mL/100 kg cement: (dosage_mL × cement_lb_per_yd3) ÷ (4536.0) [unit conversion chain]
  • If entered as fl oz/100 lb cement: (dosage_oz × cement_lb_per_yd3) ÷ 100
Step 3: Total fl oz = (dosage_oz_per_yd3) × volume_yd3
Step 4: Apply overage: Final fl oz = Total fl oz × (1 + overage% ÷ 100)
Step 5: Convert: 1 US gallon = 128 fl oz; 1 fl oz = 29.5735 mL
Step 6: mL per 100 kg cement = (Total mL) ÷ (cement_kg_total) × 100
Step 7: mL per liter concrete = (Total mL) ÷ (volume_liters)

How to Use This Admixture Dosage Calculator

Select your admixture type. Choose from the six ASTM-classified types in the dropdown. This immediately sets the typical dosage range for your reference so you know what a realistic rate looks like before you enter anything from the technical data sheet (TDS). Never dose by guessing — always start from the product TDS.
Enter your concrete batch volume and dosage rate. Enter the total volume of concrete in the batch or pour — the same number you'd give a ready-mix plant or batch plant operator. Then enter the dosage rate exactly as shown on the product's TDS. Match the unit in the dropdown to the unit on the TDS (fl oz/yd³ is most common in the US; mL/100 kg cement is standard in metric markets).
Enter cement content if using mL/100 kg dosing. If you're working from a metric TDS that expresses dosage as mL per 100 kg of cementitious material, you must enter the cement content of your mix design so the calculator can convert correctly. This is the cementitious factor — include fly ash, slag, and silica fume in the total if the TDS instructs you to.
Read your total quantity and order accordingly. The primary result is total fluid ounces with the overage factor included. Use the gallon figure to order from your supplier — most admixtures ship in 5-gallon pails, 55-gallon drums, or 275-gallon totes. Round up to the nearest container size. Never split containers across pours if you can avoid it — partial containers degrade faster once opened.

⚠ Pro Tip: The single most common admixture mistake on the jobsite is dispensing by eye or by time rather than by weight or flow meter. Overdosing a superplasticizer by 20–30% can completely collapse workability within 30 minutes, leaving you with a stiff, unworkable mix mid-pour. Always use a calibrated dispensing system. If you're adding admixture on-site, measure by mass — not by "a good splash."

Concrete Admixture Dosage Formula

Admixture dosage is expressed as a rate relative to either the concrete volume or the cementitious content of the mix. The volume-based method (fl oz/yd³) is most common in US ready-mix operations. The cement-mass-based method (mL/100 kg) is standard in metric countries and in engineered mix designs. Both are equivalent when the cement content of the mix is fixed — this calculator converts between them automatically.

Step	Formula	Example (5 yd³, 4 fl oz/yd³)
1. Base total (no overage)	Volume (yd³) × Rate (fl oz/yd³)	5 × 4 = 20 fl oz
2. Add 5% overage	Total × 1.05	20 × 1.05 = 21 fl oz
3. Convert to liters	fl oz × 0.029574	21 × 0.029574 = 0.621 L
4. Convert to gallons	fl oz ÷ 128	21 ÷ 128 = 0.164 gal

Admixture Dosage Reference Table

Total admixture required at typical dosage for common batch sizes. No overage included — add 5% for real-world ordering.
Admixture Type	Dosage Rate	1 yd³ batch	5 yd³ batch	10 yd³ batch	Total (10 yd³) in liters
Water Reducer (Type A)	4 fl oz/yd³	4 fl oz	20 fl oz	40 fl oz	1.18 L
Superplasticizer (Type F)	10 fl oz/yd³	10 fl oz	50 fl oz	100 fl oz	2.96 L
Accelerator (Non-Cl)	32 fl oz/yd³	32 fl oz	160 fl oz	320 fl oz	9.46 L
Retarder (Type B)	4 fl oz/yd³	4 fl oz	20 fl oz	40 fl oz	1.18 L
Air-Entraining Agent	1.5 fl oz/yd³	1.5 fl oz	7.5 fl oz	15 fl oz	0.44 L
Shrinkage Reducer (SRA)	48 fl oz/yd³	48 fl oz	240 fl oz	480 fl oz	14.19 L

All dosages are at the "typical" mid-range rate for each type. Always verify against the specific product TDS. Rates vary by brand and application.

Which Admixture Type Does My Project Need?

Selecting the right admixture class is the most critical decision before dosage. Each type modifies concrete behavior in a specific way — using the wrong type, or the right type at the wrong dosage, can create serious quality defects. The table below reflects classifications per ASTM C494 and ASTM C260.

ASTM admixture classification guide — select based on your project performance requirement.
Admixture Type	ASTM Class	Primary Effect	Typical Dosage (fl oz/yd³)	Common Application
Water Reducer / Plasticizer	C494 Type A	Reduces water demand 5–12% at same slump	2–6	General flatwork, improved durability
Retarding Water Reducer	C494 Type D	Reduces water demand + extends set time	2–6	Hot weather pours, long haul distance
Accelerating Water Reducer	C494 Type E	Reduces water demand + accelerates set	16–52	Cold weather, tilt-up, precast
High-Range Water Reducer (HRWR)	C494 Type F	Reduces water demand 12–30%+, high fluidity	6–20	Self-consolidating concrete, HPC
Retarding HRWR	C494 Type G	High fluidity + extended workability	6–20	Complex pours, hot climates, long hauls
Air-Entraining Agent	C260	Introduces 4–8% microscopic air bubbles	0.5–4	Freeze-thaw exposure, deicing salt resistance
Shrinkage-Reducing (SRA)	ASTM C494	Reduces drying shrinkage 25–50%	32–64	Industrial floors, bridge decks, overlays

Admixtures can be combined, but compatibility must be verified. Superplasticizers and air-entraining agents can interact — adding them in the wrong order or at incompatible doses can collapse air content. Always check with your admixture supplier for compatibility data before combining products in the same batch.

Common Mistakes When Dosing Concrete Admixtures

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Dosing by volume instead of by mass. Most admixture suppliers publish dosage by mass of cementitious content (mL/100 kg) or by concrete volume (fl oz/yd³) — not by "splashes" or "buckets." Volumetric dispensing without a calibrated meter introduces 10–20% errors that directly affect set time, workability, and air content. Use a flow meter or a calibrated dispensing pump — never a graduated cup on a windy jobsite.
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Ignoring temperature-dosage interaction. Admixture effectiveness is temperature-sensitive. A retarder dosed for 75°F ambient will dramatically over-retard at 55°F — you may have a concrete batch that won't set for 36+ hours in cool weather. A dosage that's correct for summer may be insufficient in winter. Check your product's temperature adjustment table and re-calculate for your pour-day forecast, not last week's weather.
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Using a dosage from the wrong product's TDS. Admixture dosage rates are not interchangeable between brands or even between products within the same brand's lineup. A Type F HRWR from one manufacturer may have an effective range of 4–8 fl oz/yd³ while another's runs 8–18 fl oz/yd³. Always pull the dosage from the specific product's technical data sheet — not from a generic industry table or a different project's batch tickets.
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Adding admixture directly to dry cement. Liquid admixtures must be added to the mix water or into the drum during or after the water addition — never directly to dry cement. Concentrated admixture in contact with dry cement can cause localized over-dosing, incomplete dispersion, and unpredictable set behavior. Follow the manufacturer's addition sequence on the TDS explicitly.
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Not accounting for admixture in partial batches. When you're finishing a pour with a partial drum or the last few yards of a ready-mix truck, it's tempting to skip or eyeball the admixture. That partial batch still needs a precisely proportioned dose — inconsistent dosing across a pour creates zones of different set time, strength gain, and permeability within the same slab, which is a durability problem that won't show up for years.

Frequently Asked Questions

An admixture dosage rate is the quantity of admixture added relative to either the concrete volume or the cementitious content of the mix. In the United States, it is most commonly expressed as fluid ounces per cubic yard of concrete (fl oz/yd³). In metric markets and in engineered mix designs, it is typically expressed as milliliters per 100 kilograms of cementitious material (mL/100 kg). Some products express dosage as a percentage of cement mass (e.g., 0.2% by mass). This calculator converts between all three expressions so you can work from whichever unit appears on the product's technical data sheet.
Overdosing consequences depend on the admixture type. Overdosing a superplasticizer (HRWR) causes excessive fluidity that quickly collapses into segregation — the aggregates sink and bleed water rises, producing a weak, porous surface. Overdosing a retarder can extend set time by 24–72 hours or prevent the concrete from setting entirely, especially in cooler temperatures. Overdosing an air-entraining agent creates excessive entrained air that reduces compressive strength — every 1% of air above target typically reduces 28-day strength by 3–5%. In all cases, the remedy is usually to reject the batch and order new concrete, since there is no practical way to reverse an overdosed admixture in a placed slab.
Yes, but there are important limitations. Adding water on-site to loosen stiff concrete is almost always prohibited because it changes the water-cement ratio and reduces strength. However, adding pre-approved admixtures on-site — particularly HRWRs to restore slump lost during transit — is an accepted practice in the industry, and many concrete specifications explicitly allow it. Any on-site addition must be noted on the batch ticket, the truck must be turned at high speed for a specified period (typically 30 additional revolutions at mixing speed) to ensure full dispersion, and the total dosage including plant-added admixture must not exceed the maximum allowed by the product TDS or the mix design specification. Do not exceed the allowable maximum just because the concrete looks stiff.
Both are water reducers under ASTM C494, but their degree of water reduction differs significantly. Type A (normal water reducer / plasticizer) typically reduces water demand by 5–12% at the same slump, which translates to a modest improvement in strength and durability. Type F (high-range water reducer / superplasticizer) reduces water demand by 12–30% or more, enabling either much higher workability at the same water content or dramatically higher strength at reduced water content. Superplasticizers are used in high-performance concrete (HPC), self-consolidating concrete (SCC), and precast operations where very low water-cement ratios are required. Type A admixtures are the workhorses for general ready-mix concrete on everyday flatwork and foundations.
If you live in a climate that experiences freezing temperatures, yes — air entrainment is not optional for exposed flatwork. The microscopic air bubbles (typically 4–7% by volume) provide relief voids that absorb the expansion pressure water exerts when it freezes inside the concrete matrix. Without air entrainment, freeze-thaw cycling causes scaling — the top surface flakes off in sheets, typically starting within 2–5 years. ACI 318 and most state DOT specifications require air-entrained concrete for all exterior flatwork in freeze-thaw exposure zones. If your ready-mix supplier is providing the concrete, confirm that air entrainment is included in the mix specification, and request an air content test on delivery.
Temperature directly affects the rate of cement hydration, which changes how quickly and completely admixtures are consumed. In hot weather (above 85°F / 30°C), cement hydrates faster, which means retarders are consumed more quickly than expected — you may need to increase the retarder dosage to maintain the target set time. Conversely, in cold weather (below 50°F / 10°C), hydration slows, making retarders dramatically more effective — a standard summer dosage can over-retard a cold-weather pour by 12–24 hours. Air-entraining agents are also temperature-sensitive: higher temperatures require higher doses to achieve the same air content. Always consult the product TDS for temperature-adjusted dosage tables, and communicate the anticipated pour temperature to your admixture supplier if you're uncertain.
SRAs work by reducing the surface tension of the pore solution inside concrete, which reduces the internal stresses that develop as concrete dries and shrinks. A typical SRA reduces drying shrinkage by 25–50% compared to an untreated mix. This directly reduces crack width and frequency in applications where cracking is a functional problem — industrial floors with tight flatness tolerances, bridge decks subject to deicing chemicals, parking garage decks, and concrete overlays where cracking leads to rapid delamination. SRAs are high-dosage admixtures (32–64 fl oz/yd³ is common) and relatively expensive, so they're not specified for general flatwork — the benefit needs to justify the cost. They're also not a substitute for proper joint placement, curing, and subgrade preparation.
Most liquid admixtures are available in three container sizes: 5-gallon pails (suitable for small jobs and bagged-concrete applications), 55-gallon drums (standard for mid-size projects and small contractors), and 275-gallon intermediate bulk containers (IBCs or totes, typically used by ready-mix plants). Some products are also available in 1-gallon jugs for testing and small trial batches. For on-site use with bagged concrete, 5-gallon pails are most practical. For ready-mix operations, IBCs minimize handling and cost per gallon. When calculating how many containers to order, round up to the next full container — partial containers degrade more rapidly once opened and are rarely economical to return.
Yes — most liquid admixtures have a shelf life of 12 months from the date of manufacture when stored properly. Some products, particularly certain types of air-entraining agents, can degrade within 6 months. The main enemies are temperature extremes and contamination. Store admixtures in a dry, temperature-controlled environment between 40°F and 100°F (4°C–38°C). Freezing many admixtures causes irreversible separation or crystallization that cannot be corrected by thawing and stirring. Always check the lot number and manufacture date before using material from storage, and never mix admixtures from different lots without testing. If you suspect an admixture has been compromised, have a fresh sample tested by your supplier before using it on a critical pour.
To convert from mL/100 kg cement to fl oz/yd³, you need the cement content of your mix in pounds per cubic yard. The conversion is: fl oz/yd³ = (mL/100 kg) × (cement content in lb/yd³) ÷ 4536. The constant 4536 comes from combining the unit conversions: 100 kg = 220.46 lb, and 1 fl oz = 29.5735 mL — combined as (220.46 × 29.5735 ≈ 6520), but expressed per unit of concrete volume it resolves to 4536 when using lb/yd³. For example, a dosage of 300 mL/100 kg with a cement content of 650 lb/yd³ equals (300 × 650) ÷ 4536 ≈ 43 fl oz/yd³. This calculator handles this conversion automatically when you select the mL/100 kg dosage unit and enter your cement content.