Tools › User guides › Concrete Mix Design
The Concrete Mix Design Calculator proportions a concrete mix by IS 10262:2019 (default), IS 10262:2009, IS 10262:1982 or ACI 211.1-91: target mean strength, w/c ratio, water, cement, fly ash / GGBS, admixture, sand and coarse aggregate per m³, moisture correction, per-bag quantities and trial mixes, with a PDF calculation sheet.
Open the Concrete Mix Design Calculator ›
Pick IS 10262:2019 (current code), IS 10262:2009, IS 10262:1982 or ACI 211.1-91. The table “How the methods differ” at the bottom of the tool compares the steps. Section 1 (Project, Client, Prepared by, Revision) only prints on the PDF.
| Field | What to enter | Typical value | Tip |
|---|---|---|---|
| Grade of concrete | fck, N/mm² (M10 – M60). | M20 / M25 | |
| Type of concrete | RCC or PCC. | RCC | Sets the IS 456 Table 5 durability limits. |
| Exposure condition | Mild, Moderate, Severe, Very severe, Extreme. | Moderate | Limits max w/c and min cement content. |
| Type of cement | OPC 33/43/53, PPC, PSC. | OPC 43 / PPC | |
| Maximum nominal size of aggregate | 10 – 50 mm. | 20 mm | |
| Type of coarse aggregate | Crushed angular … rounded gravel. | Crushed angular | Rounded aggregate needs less water. |
| Workability — slump (mm) | Required slump. | 75 – 100 (RCC), 100 – 150 (pumped) | Water is increased 3 % per 25 mm above 50 mm. |
| Workability — compacting factor | Only for the 1982 method. | 0.80 | |
| Degree of site control | Very good / Good / Fair. | Good | Sets the standard deviation from the code table. |
| Standard deviation S — optional | Your own value from ≥ 30 test results. | Blank | Blank = code table (e.g. 4 N/mm² for M20–M25). |
| Placing | Normal or Pumpable (reduce coarse aggregate 5 / 10 %). | Normal | |
| Air entrainment | Non air-entrained or air-entrained for the exposure. | Non air-entrained |
| Field | What to enter | Typical value | Tip |
|---|---|---|---|
| Specific gravity of cement | From the cement test. | 3.15 (OPC), 2.9 (PPC) | |
| Specific gravity of fine aggregate (SSD) | Lab test. | 2.6 – 2.7 | |
| Specific gravity of coarse aggregate (SSD) | Lab test. | 2.7 – 2.8 | |
| Fine aggregate grading zone (IS 383) | Zone I – IV from the sieve analysis. | Zone II | |
| Fineness modulus of sand | From the sieve analysis. | 2.4 – 3.0 | Used by the ACI method. |
| Dry-rodded bulk density of coarse aggregate | kg/m³ — ACI method. | 1550 – 1650 | |
| Water absorption — fine / coarse (%) | Lab test. | 1.0 / 0.5 | |
| Total moisture at site — fine / coarse (%) | Measured at site on the day. | Same as absorption = no correction | The calculator corrects water and aggregate weights for free moisture. |
| Field | What to enter | Typical value | Tip |
|---|---|---|---|
| Chemical admixture | None, Plasticizer, Superplasticizer. | Superplasticizer | |
| Water reduction by admixture (%) | From the manufacturer. | Plasticizer 5–10, SP 20–30 | |
| Dosage (% by mass of cementitious) | From the manufacturer. | 0.5 – 1.5 | |
| Specific gravity of admixture | From the data sheet. | 1.08 – 1.2 | |
| Mineral admixture | None, Fly ash (IS 3812), GGBS (IS 16714). | ||
| Replacement (% of cementitious) | Fly ash 20–30, GGBS 30–50 | ||
| Specific gravity of mineral admixture | Fly ash 2.2, GGBS 2.9 | ||
| Increase cementitious content | By 10 % (code suggestion) or no increase. | By 10 % |
| Field | What to enter | Typical value | Tip |
|---|---|---|---|
| Free water–cement ratio from | Auto (from the code curves, capped by IS 456) or Enter my own value. | Auto | |
| Fig. 2 curve — 28-day cement strength | The strength band of your cement (IS 4031 test), or Fig. 1 if not known. | Curve D for OPC 43 | |
| Your w/c ratio | Only when “Enter my own value” is chosen. | 0.40 – 0.50 | |
| Volume of concrete to batch (m³) | For the batch quantities. | 1, or 0.025 for a cube trial |
The summary shows target mean strength, w/c ratio, water, cement, fly ash / GGBS, fine and coarse aggregate (SSD), admixture and the mix ratio by mass. Below are the Quantities (per m³, per 50 kg bag, and for your batch volume, with the site-moisture correction), the Trial mixes (w/c ± 10 %) and the full Step-by-step calculation. A calculated mix is only the starting point: make trial batches, check slump and cube strength, and adjust before use.
IS 10262:2019 is the current Indian code and the default. Use the 2009 or 1982 edition only to check an older design, and ACI 211.1 for ACI-based specifications.
IS 456 Table 5 sets a minimum cement content and a maximum w/c ratio for the exposure. The calculator raises the cement to meet them.
Yes. Every code requires trial batches to confirm workability and strength before the mix is used.