Concrete Mix Design Calculator

Help The EngineerConcrete Mix Design Report • IS 10262:2019
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IS 10262 : 2019 • IS 456 : 2000

Concrete Mix Design Calculator

Enter your grade, exposure and material test results. Get cement, sand, aggregate and water per m³, field-corrected, with all IS checks.

M20 – M40Field correctionsStep-by-stepFree
  1. 1Requirements
  2. 2Cement & w/c
  3. 3Aggregates
  4. 4Result
1

Design requirements

Grade, exposure and workability
💡 The strength you need. Slabs, beams and columns in houses usually use M20 or M25.
💡 Where will the concrete be? Not sure? See the "Exposure guide" in the cheat sheet below. Inside a building = Mild; outdoors with rain = Moderate.
💡 The largest stone size. 20 mm is used for most RCC work.
💡 How runny the concrete is. Slabs and beams: 50–100 mm. Pumped concrete: 75–100 mm or more.
💡 Crushed machine stone (gitti) = Angular. River pebbles = Rounded.
💡 Choose Yes if the concrete will be placed with a concrete pump.
2

Cement & water-cement ratio

Read w/c from IS 10262 Fig. 1 for your cement
💡 Written on the cement bag (OPC 43, OPC 53 or PPC).
💡 Use 3.15 for OPC and 2.90 for PPC if you have no test value.
💡 Less water = stronger concrete. A typical starting value fills in when you change the grade. It must not be more than the IS 456 limit (checked on the right).
💡 A chemical (plasticizer) that makes concrete flow with less water. Choose Yes if you add one.
3

Aggregate test results

From your lab tests (IS 2386, IS 383)
💡 From the lab test. Typical sand: 2.60 – 2.70.
💡 From the lab test. Typical stone: 2.60 – 2.80.
💡 From the sand sieve test. Most river sand is Zone II; finer sand is Zone III.
💡 Usual split for 20 mm: 60% of 20 mm and 40% of 10 mm.
💡 How much water dry sand soaks up. Typical 1 – 2%. Use 0 if not known.
💡 How much water dry stone soaks up. Typical 0.5 – 1%. Use 0 if not known.
💡 Extra water on wet sand at site. Dry sand = 0; damp sand 2 – 5%.
💡 Extra water on wet stone. Usually 0 – 1%.
📋 Cheat sheet: exposure, slump and typical values

Exposure guide (IS 456 Table 3)

MildInside buildings, protected from rain (not near the sea).
ModerateOutdoors with rain, buried in normal soil, always under water.
SevereAlternate wetting and drying, heavy rain, coastal areas.
Very severeSea-water spray, corrosive fumes, aggressive soil.
ExtremeTidal zone, direct contact with aggressive chemicals.

Slump guide (IS 456 cl. 7.1)

25 – 75 mmPCC, footings, lightly reinforced slabs and beams.
50 – 100 mmHeavily reinforced slabs, beams, columns, walls.
75 – 100 mmPumped concrete.
100 – 150 mmTremie (under-water) concrete, very congested steel.

Typical values (if not tested)

Sp. gravity: OPC / PPC3.15 / 2.90
Sp. gravity: sand2.60 – 2.70
Sp. gravity: stone2.60 – 2.80
Water absorption: sand / stone1 – 2% / 0.5 – 1%
Surface moisture: damp sand2 – 5%
Plasticizer / superplasticizer5–10% / 15–25% water cut

Good to know

  • Lower w/c = stronger, more durable concrete.
  • Cement should stay below 450 kg/m³; use a plasticizer for high slump.
  • 1 bag of cement = 50 kg.
  • For M25 and above, IS 456 recommends a design mix (not 1:1:2).
  • Always make trial cubes and test at 7 and 28 days.
Full calculation, step by step (IS 10262)
Important: This calculator gives a trial mix as per IS 10262:2019. Always confirm it with trial batches and 7/28-day cube tests before use on site. Specific gravities, absorption and moisture must come from your own material tests.
MIX PROPORTION BY WEIGHT (C : FA : CA)
1 : 1.70 : 2.22
CementSandStoneWater
M25w/c 0.47Target 31.6 N/mm²
Quantity of concrete m³ field-corrected

Design inputs

IS code checks

Generated free at www.helptheengineer.com, Concrete Mix Design Calculator. Trial mix only: confirm with trial batches and cube tests before use. © Help The Engineer
1 : 1.70 : 2.22
Cement 8.9 bags/m³
See result ↓