The concrete admixture tools here are 5 free tools: 3 calculators that turn a dose, a water content or a mix into batch quantities in metric and US units, and 2 request forms for suppliers or providers.
The tools serve producers, specifiers, lab staff and contractors. The additives behind these tools are covered under concrete additives.
A dose of 1.0 fl oz/cwt equals 65.2 mL/100 kg, w/cm counts SCMs as ACI CODE-318-25 does, EN 934-2:2009+A1:2012 caps an admixture at 5 % by mass of the cement content, and delivered lots are checked against EN 934-1:2008 Table 1 tolerances.
What Do the Concrete Admixture Tools Cover?#
The concrete admixture tools cover 3 calculations and 2 requests: dose to batch quantity, w/c and w/cm with SCMs, mix proportions, a supplier quote request and a provider request.
The 5 tools are compared below by question, inputs, output and referenced documents.
| Tool | What it answers | Inputs | Output | References named |
|---|---|---|---|---|
| admixture dosage calculator | How much admixture per batch | Dose and basis (mL/100 kg, fl oz/cwt, % by mass of binder, as supplied or solids), cementitious content | Quantity per m³ and per yd³ | 1 fl oz/cwt = 65.2 mL/100 kg; 1 kg/m³ = 1.6856 lb/yd³ |
| water-cement ratio calculator | w/c and w/cm of a batch, SCMs included | Free water, cement, SCM masses | w/c, w/cm and a code check | ACI CODE-318-25 Table 19.3.2.1; EN 206-1:2026 Annex F (informative); IS 456:2000 Table 5 |
| concrete mix design calculator | Trial mix proportions | Strength, exposure, aggregate and SCM inputs | Batch masses per m³ and per yd³ | ACI PRC-211.1-22 with ACI 211.1-91 tables; IS 10262 mode; EN 206-1:2026 check |
| request quotes from concrete admixture suppliers | Who supplies a product to a specification | Product type, standard required, quantity and packaging, delivery country, plant type | A request routed to independent suppliers | ASTM C494/C494M-24, EN 934-2:2009+A1:2012, IS 9103:1999 as "standard required" choices |
| find a concrete mix design, testing or specialty placement provider | Who designs, tests or places a special mix | Service type, concrete type, location | A request routed to independent providers | None |
Tools are free to use. Requests go to independent suppliers and providers; no company is named or ranked.
Three calculators: dose, water and mix proportions#
The dosage calculator converts mL/100 kg, fl oz/cwt and % by mass of binder into batch quantities, the water-cement calculator computes w/c and w/cm, and the mix design calculator proportions a trial mix. The ratios are w/c = free water / cement and w/cm = free water / (cement + SCMs). ACI CODE-318-25 computes w/cm on all cementitious materials, fly ash, natural pozzolans, silica fume and slag cement included, and its limits do not apply to lightweight concrete. EN 206-1:2026 Annex F, also named in the code check, is informative, with national provisions governing.
The mix design calculator runs an ACI mode on ACI PRC-211.1-22 (2022), the current ACI proportioning guide, with tables labeled ACI 211.1-91, plus an IS 10262 mode and an EN 206-1:2026 check (CEN approval 2026-01-19, superseding EN 206:2013+A2:2021). The proportioning method itself is worked through under concrete mix design.
Two request forms: products and services#
The quote request sends one specification for an admixture, SCM, fiber or pigment to independent suppliers, and the provider request goes to independent providers for mix design and trial batching, testing or specialty placement. Its 5 fields are listed below.
- Product type: ASTM C494 type, SCM class, fiber type and length, pigment color
- Standard required
- Quantity and packaging: IBC, drum, bulk tanker, big bag
- Delivery country
- Plant type: ready-mix, precast, contractor, distributor
Provider labs run fresh and durability tests, ASR included; specialty placement covers shotcrete, pervious, cellular and cold-weather concrete.
Which Dose Bases Do Admixture Calculators Use?#
Admixture calculators work with 7 dose bases, from mL/100 kg (fl oz/cwt) of cementitious material for liquid admixtures to % by volume for fibers, and a dose is not batchable until its basis is stated. A mass dose is as supplied or as solids. Each admixture function and the basis it is dosed on is listed under concrete admixtures.
The 7 dose bases are compared below with their US pair and factor.
| Basis | Used for | US pair and factor |
|---|---|---|
| mL/100 kg of cementitious material | Liquid admixtures dosed by volume per mass of cementitious material | fl oz/cwt; 1 fl oz/cwt = 65.2 mL/100 kg |
| % by mass of cement or binder, as supplied or as solids | Admixtures dosed by mass | Same in both systems; solids = as supplied × solids content |
| L/m³ of concrete | Admixtures dosed per volume of concrete | gal/yd³; 1 L/m³ = 0.2020 gal/yd³ |
| kg/m³ of concrete | Dry materials per volume of concrete | lb/yd³; 1 kg/m³ = 1.6856 lb/yd³ (1 lb/yd³ = 0.5933 kg/m³) |
| % replacement | SCMs, expansive components | Same in both systems |
| % by volume | Fibers | Same in both systems |
| Dilution ratio | Foaming agents | Same in both systems |
The final dose is set by trial batches with the job materials.
Converting metric and US dose units: a worked example#
One fluid ounce per hundredweight equals 65.2 mL per 100 kg, and 1 kg/m³ equals 1.6856 lb/yd³, so a dose converts exactly once the factor and the cementitious content are known.
Worked example, inputs: 350 kg/m³ (590 lb/yd³) of cementitious material, all cement; volume dose 65.2 mL/100 kg (1.0 fl oz/cwt); mass dose 1.0 % by mass of cement as supplied; product solids 40 %.
- Volume dose: 3.5 × 65.2 = 228 mL per m³ (5.90 cwt × 1.0 = 5.9 fl oz per yd³).
- Mass dose: 1.0 % of 350 kg = 3.5 kg/m³ (5.90 lb/yd³) as supplied, or 1.4 kg/m³ (2.36 lb/yd³) as solids.
- Ceiling: the EN 934-2 limit of 5 % by mass of the cement is 17.5 kg/m³ (29.5 lb/yd³).
Water in liquid admixtures and the w/cm count#
Water in a liquid admixture counts toward the mixing water, and uncounted admixture water raises the real w/cm. The ConBlock MIC data sheet deducts 1 gal of batch water per gal of product (1 L per L). Code limits for the water-cement ratio by exposure class are explained on their own page.
How Do the Tools Work Together, From Mix to Quote?#
The tools run in the order a mix is developed: proportion, check w/cm, convert the dose, confirm in trial batches, request quotes against one specification, then check each delivered lot against its declaration. The 6 steps are listed below.
- Proportion the mix with the mix design calculator.
- Check w/c and w/cm with SCMs counted in the water-cement calculator.
- Convert the admixture dose with its basis in the dosage calculator.
- Confirm slump, air and strength in trial batches, through the provider request where a lab is needed.
- Request quotes against one specification through the quote request.
- Check each delivered lot against the declaration, as in Table 3.
A calculated dose is a starting value: the Plastol 6400 data sheet states that dosage depends on the materials and that trial mixes with local materials verify plastic and hardened performance.
Checking delivered admixture lots against the standard#
Two documents give lot checks for delivered admixtures: ASTM C494/C494M-24 Level 3 uniformity and equivalence tests, which apply only when the purchaser specifies them, and the general requirements of EN 934-1:2008. ASTM C494/C494M-24 is active, covers eight types (A, B, C, D, E, F, G and S) and adds Level 1 initial approval and Level 2 limited retesting.
The lot checks are compared below with the tolerance each one sets.
| Document (edition) | Check | Requirement or tolerance |
|---|---|---|
| ASTM C494/C494M-24 Level 3 | Uniformity and equivalence (for example solids, density, infrared) | Only when specified by the purchaser |
| EN 934-1:2008 Table 1 | Density | Declared value ± 0.03 when the declared density is above 1.10, otherwise ± 0.02 |
| EN 934-1:2008 Table 1 | Dry material content | 0.95T to 1.05T where the declared value T is at least 20 %, otherwise 0.90T to 1.10T |
| EN 934-1:2008 Table 1 | pH | Declared value ± 1 |
| EN 934-1:2008 Table 1 | Total chlorine and water-soluble chloride | At most 0.10 % by mass or not above the declared value |
| EN 934-1:2008 Table 1 | Alkali content | Not above the declared maximum |
| EN 934-1:2008 | Homogeneity, color, infrared spectrum | As declared by the manufacturer |
EN 934-2:2009+A1:2012 is harmonised under Regulation (EU) No 305/2011, and the quote request lists it as EN 934-2 with its declaration of performance. For Indian requests, IS 9103:1999, the Indian specification for concrete admixtures with five types, is active, reaffirmed 2018, with two amendments (BIS). The full set of concrete admixture standards is compared in the standards section.
What a Calculated Dose Does Not Replace#
A calculated dose is a starting point for trial batches, not an approval: ASTM C494/C494M-24 approves an admixture by Level 1 testing against its Table 1 requirements. NRMCA 2PE004-26 (March 2026) notes that ACI CODE-318-25 (publication year 2025) and ACI SPEC-301-20 contain no minimum cementitious content and use trial mixture data from within 24 months.
Coverage calculators for curing compounds and sealers are not part of these tools, and concrete volume and bag-count estimates for small jobs are not offered here.
Is a calculated dose a standard requirement?#
No: a product standard sets a ceiling or a performance test, not the job dose. EN 934-2:2009+A1:2012 limits an admixture to not more than 5 % by mass of the cement content (3.2.1); the job dose comes from the data sheet range and trial mixes.