Calculate the exact admixture quantity in fluid ounces, gallons, and pounds for any concrete volume — water reducers, superplasticizers, air-entraining agents, accelerators, retarders, fly ash, silica fume, and more. Based on ASTM C494 dosage rates. 2026 USA pricing included.
A concrete admixture quantity calculator converts a target admixture dosage rate — expressed in the US standard unit of fluid ounces per hundredweight (oz/cwt) of cement — into the actual volume and weight of admixture needed for a given concrete pour. The "hundredweight" (cwt) = 100 lbs of cement, so a 4 oz/cwt dosage for a 6-bag mix (564 lbs cement/CY) means 4 × 5.64 = 22.56 fl oz per cubic yard of concrete. This calculator handles that math across any number of cubic yards, converts results to gallons and pounds for ordering, and applies your chosen admixture price for a full cost estimate — critical for batch plant operators, ready-mix dispatchers, and concrete contractors managing material budgets.
Unlike metric systems that use mL per 100 kg of cement, the USA expresses admixture dosage in fluid ounces per 100 lbs (cwt) of cementitious material. This unit is baked into every ASTM C494-listed product data sheet and is how ready-mix batch plants programme their admixture dispensers. To convert: multiply the dosage (oz/cwt) × cement content (lbs/CY) ÷ 100 to get oz per CY. Then divide by 128 to get gallons per CY. This calculator performs all conversions automatically including density-based weight calculations using your admixture's specific gravity.
This reference table covers all ASTM C494 chemical admixture types with typical dosage ranges, expected concrete performance effects, and 2026 USA pricing from major suppliers (BASF MasterGlenium, Sika ViscoCrete, GCP Daracem, Euclid Chemical):
| ASTM Type | Admixture Class | Typical Dosage (oz/cwt) | Key Benefit | W/C Reduction | 2026 Price ($/gal) | Common Use |
|---|---|---|---|---|---|---|
| Type A | Water-Reducing | 2–6 | Workability ↑, water ↓ | 5–12% | $4–$8 | Flatwork, foundations |
| Type B | Retarding | 2–6 | Delays set time | 0–5% | $5–$9 | Hot weather, large pours |
| Type C | Accelerating (Non-Cl) | 16–64 | Faster strength gain | 0–5% | $3–$7 | Cold weather concrete |
| Type D | Retarding + WR | 2–8 | Workability + set delay | 5–12% | $5–$10 | Summer slabs, decorative |
| Type E | Accelerating + WR | 4–16 | Early strength + workability | 5–12% | $5–$10 | Winter construction |
| Type F | HRWR / Superplasticizer | 3–12 | High workability / flowability | 12–30% | $8–$18 | Structural, SCC, bridges |
| Type G | HRWR + Retarding | 3–12 | Flow + extended set time | 12–30% | $10–$20 | Precast, hot weather SCC |
| ASTM C260 | Air-Entraining (AEA) | 0.5–3 | Freeze-thaw resistance | N/A | $6–$10 | Pavements, driveways, cold climates |
| SRA | Shrinkage-Reducing | 1–2% by wt | Reduces drying shrinkage 30–50% | N/A | $15–$25 | Slabs, toppings, bridges |
| CaCl₂ | Calcium Chloride (Type C) | 16–32 | Fastest set acceleration | N/A | $1–$3 | Cold weather — non-rebar only |
SCMs are mineral admixtures that partially replace Portland cement, reducing cost and improving durability. ACI 318-19 and ACI 211.1 govern their use in US concrete design:
| SCM Type | ASTM Standard | Typical Replacement | Strength Effect | Durability Benefit | 2026 Price ($/ton) |
|---|---|---|---|---|---|
| Fly Ash Class F | ASTM C618 | 15–35% | Slower early, same 28-day | Sulfate resistance, reduced heat | $80–$140 |
| Fly Ash Class C | ASTM C618 | 15–40% | Good early strength | Reduced heat of hydration | $60–$110 |
| Silica Fume | ASTM C1240 | 5–10% | Very high early + long-term | Chloride resistance, low permeability | $400–$700 |
| GGBS / Slag | ASTM C989 | 20–50% | Slower early, higher long-term | Excellent sulfate + chloride resistance | $90–$160 |
| Metakaolin | ASTM C618 (N) | 10–20% | Good early + long-term | ASR mitigation, low permeability | $600–$900 |
Type A WRAs remain the most widely used admixture in US concrete — used in an estimated 70% of all ready-mix deliveries. The 2026 market price for BASF MasterPolyheed, GCP Eclipse, and equivalent products ranges from $4–$8 per gallon. A typical 10 CY pour at 564 lbs cement/CY and 4 oz/cwt dosage requires approximately 1.76 gallons — a material cost of only $7–$14, yet delivering 8–12% water reduction and significant workability improvement.
High-Range Water Reducers (ASTM C494 Type F) are essential for self-compacting concrete, high-strength mixes (>5,000 PSI), and bridge deck pours. Polycarboxylate ether (PCE) based products like BASF MasterGlenium, Sika ViscoCrete, and Euclid Eucon 1037 dominate the 2026 US market at $8–$18 per gallon. These admixtures can reduce water-to-cement ratio by up to 30%, enabling 28-day strengths of 8,000–12,000 PSI from standard materials. Dosage is highly sensitive — exceeding 12 oz/cwt can cause excessive retardation or segregation.
AEAs (ASTM C260) are mandatory in freeze-thaw exposed concrete per ACI 318-19 — any US region with 25+ freeze-thaw cycles per year. Target air content for pavement is 6–7.5%; for structural concrete 4–6%, varying by aggregate size per ACI 211.1 Table 6.3.3. At just 0.5–3 oz/cwt, a 10 CY pour requires only 0.11–0.67 gallons of AEA — typically $0.66–$6.70 in material cost. The 2026 Midwest and Northeast markets require AEA in virtually all exterior flatwork specifications.
All chemical admixtures have a maximum allowable dosage per ASTM C494 — exceeding it can cause excessive retardation (concrete stays plastic for 24+ hours), segregation, air-void instability, or strength loss. Always obtain a product data sheet (PDS) from the manufacturer and confirm dosage with a trial batch or concrete mix design by a licensed engineer for structural applications. Admixture compatibility — particularly between HRWR and AEA combinations — must be tested with your specific cement source, as performance varies significantly by cement chemistry and water quality. Never assume dosage from one project transfers directly to another.
Standards and sources used for 2026 admixture dosage rates, pricing, and compatibility guidance
ASTM C494 is the governing US specification for chemical admixtures (Types A–H) defining performance requirements, test methods, and compliance criteria referenced throughout this calculator for dosage type classifications.
Visit ASTMACI 212.3R is the American Concrete Institute's comprehensive guide to chemical admixtures — covering dosage rates, compatibility testing, batch plant dispensing, and performance expectations for all admixture classes used in US concrete practice.
Visit ACIASTM C618 classifies fly ash (Class C and F) and natural pozzolans for use in concrete — defining chemical composition, fineness, and performance requirements referenced for SCM replacement rate calculations in this tool.
Visit ASTM