Trial 2 · revised water
Requested w/b 0.420375.5 kg/m³ binder157.7 kg/m³ free water · actual w/b 0.420Proposed only · measure workability and strength.
THE CONCRETE MIX DESIGN LAB
Concrete Mix Design Calculator
Choose a grade. Set your quantity. See every ingredient, then explore the science behind your concrete mix ratio.
Absolute-volume method
Built around the science
Built around the science
01 Choose your concrete grade
What does the grade mean?M30 means 30 MPa characteristic cube strength at 28 days. Each grade needs a material-specific mix; it has no single fixed ratio.
02 How much concrete?
Design volume. No waste allowance is added automatically.
Total batch weight2,458.55 kg
Sum of all materials to weigh
Designed concrete volume1 m³
1,000 litres
03 Your M30 mix
Quantities for your 1 m³ batch · Preliminary trial
Sand and stone include their entered moisture. Water is the amount to add at the mixer; water already in aggregates and admixture is accounted for.
Binder : sand : stone 1 : 1.82 : 3.29SSD proportions by massWater / binder 0.42Free water ÷ total binder
Based on example material properties. Confirm performance with physical trials; actual yield needs measured fresh density.
GO DEEPER
Refine your concrete mix design
Review the material assumptions, follow each calculation and prepare a physical trial.
YOUR MIX, EXPLAINED
M30 concrete
Target mean strength38.25 MPa
Total binder375.5 kg/m³
Free water157.7 kg/m³
Final water/binder0.420
Quantities, inputs, calculation steps and references.
FOLLOW THE SCIENCEExplore a decision. Measure a trial. Compare the evidence.
01 / COMPOSITION
Inside one cubic metre
Shares by absolute volume, including air.
Absolute volume uses specific gravity. It is not loose bucket volume. ¹ Water carried by an admixture stays within its product share.
02 / STRENGTH RELATIONSHIP
Water changes the outcome
Approximate Figure 1 readings · 28-day cube strength
33–<4343–<53≥53cement strength · MPa
Approximate reference 0.450 → ~35.5 MPa
The curves are an approximate redraw of IS 10262:2019 Figure 1, not measured results for your mix. SCM blends need material-specific trials.
SSD ratio by mass 1 : 1.82 : 3.29
Total binder : fine aggregate : coarse aggregate.
This proportion belongs to these inputs; it is not a universal M30 recipe.
DESIGN WITH THE CURVE
Shape the aggregate blend.
Drag the target points. Explore a sand–stone blend. See the batch change.
Illustrative sieve data20 mm context · two materials
SandStoneYour target · draggableProposed blendCurrent mix share
Percent retained · reveal the size fractions
The cumulative curve can hide a gap or a concentration. These bars show mass between adjacent sieves, including pan and oversize. A close target fit does not establish packing density or workability.
Blend 0.48%Target 0.52%
For an interval: passing at the larger sieve − passing at the smaller sieve. All fractions sum to 100.0%. These are user targets, not a specification envelope. FHWA-sponsored grading research ↗
4.75 mm sieveTarget 41.8%Proposed 37.7%
Neighbouring points keep the curve ordered.
Stone 64.5% · dry aggregate mass
More stoneMore sand
2.3 percentage points RMS difference from your target
One blend share must work across every sieve; some target shapes cannot be matched exactly.
LIVE BATCH PREVIEW
From the curve to the mixer
| Quantity | Current mix | Proposed | Change |
|---|---|---|---|
| Sand · as batched | 684.6 | 684.6 | — |
| Stone · as batched | 1236.9 | 1236.9 | — |
| Water to add | 157.7 | 157.7 | — |
| Total binder | 375.5 | 375.5 | — |
Binder and free-water target stay fixed. Aggregate volumes and wet batching quantities are recalculated using your SSD specific gravities, absorption and moisture.
Enter sieve-test data & target values 10 sieve sizes
Cumulative percent passing by oven-dry mass. Editing source values marks them as user-entered; no laboratory verification is implied.
| Sieve mm | Sand % | Stone % | Target % | Blend % |
|---|---|---|---|---|
| 0.075 | 0.5 | |||
| 0.15 | 2.0 | |||
| 0.3 | 5.6 | |||
| 0.6 | 14.7 | |||
| 1.18 | 23.4 | |||
| 2.36 | 30.8 | |||
| 4.75 | 37.7 | |||
| 10 | 56.2 | |||
| 20 | 97.4 | |||
| 40 | 100.0 |
How the graph changes the calculation
For each sieve, blend passing = x × sand passing + (1 − x) × stone passing, where x is the sand fraction of oven-dry aggregate mass. Fit target finds the least-squares fraction across all displayed sieves, limited to 1–99% sand in this application.
For volume accounting, each dry share is multiplied by (1 + absorption) and divided by its bulk SSD specific gravity. The resulting volume fractions allocate the available aggregate volume. The fitted share replaces the IS table split and its optional coarse reduction.
The editable target and example curves are exploratory. This is not an IS 383 grading-envelope check, packing-density optimization or strength prediction. Constituent suitability, water demand, workability and physical trials still need evaluation.
Reference: combining aggregate gradations, Iowa DOT IM 531EXPERIMENT / PREDICT QUANTITIES, THEN TEST PERFORMANCE
Change one decision. Follow every consequence.
Pin a mix, choose what stays fixed, then move the ratio. The candidate stays separate until you apply it.
Pinned M30 · ModerateW 157.7 kg/m³B 375.5 kg/m³w/b 0.420
Binder response to requested w/bCalculated mass · not predicted strength
Green: no action-level limit triggered. Amber: a governing limit or design action needs review. The plotted sweep covers 0.25–0.65; the control allows 0.20–0.70. Any previous binder uplift is already represented in the pinned mass and is not applied again.
01 / FREE WATER157.7 kg/m³Held at the baseline
02 / BINDER375.5 kg/m³Ratio demand, then minimum content
03 / REMAINING VOLUME709.8 L/m³1 m³ − paste − entrapped air
| Quantity | Pinned | Candidate | Change |
|---|---|---|---|
| Total free water kg/m³ | 157.7 | 157.7 | 0.0 |
| Total binder kg/m³ | 375.5 | 375.5 | 0.0 |
| Actual water/binder | 0.420 | 0.420 | 0.000 |
| Paste volume L/m³ | 280.2 | 280.2 | 0.0 |
| Fine aggregate · SSD kg/m³ | 684.6 | 684.6 | 0.0 |
| Coarse aggregate · SSD kg/m³ | 1236.9 | 1236.9 | 0.0 |
| Mixer water kg/m³ | 157.7 | 157.7 | 0.0 |
All candidate assumptions and checks
Admixture water contribution is set to 0%. Enter the supplier’s measured water fraction when applicable; do not assume a liquid product is water-free.
Material data and project conformity still require verification even when no numerical limit is triggered.
IS 10262 trial planner · keep revised water fixed
After Trial 1, adjust water and/or admixture to address observed workability. Trial 2 retains the preselected ratio; Trials 3 and 4 explore about −10% and +10% of that ratio at the same revised water. Here the pinned actual ratio is the starting value. These are proposed batches, with no assumed strength or slump results. IS 10262:2019 §5.8 ↗
Enter the revised SSD free-water budget. Edit admixture in the main design and re-pin if its dosage also changes.
Trial 3 · −10% ratio
Requested w/b 0.378417.3 kg/m³ binder157.7 kg/m³ free water · actual w/b 0.378Proposed only · measure workability and strength.
Trial 4 · +10% ratio
Requested w/b 0.462341.4 kg/m³ binder157.7 kg/m³ free water · actual w/b 0.462Proposed only · measure workability and strength.
WATER / FROM MATERIAL CONDITION TO BATCH QUANTITY
The water in your mix arrives from several places.
Start with the free-water budget, then account for aggregate moisture and the water inside liquid admixture. Quantities below follow the current design.
157.73 + (0.00) + (0.00) + 0.00 = 157.73 kg/m³
Amber negative contributions represent absorption demand. They increase the water to add. This diagram shows signed amounts; bar lengths represent magnitude.
01 / SSD DESIGN MASS684.65 kgPores saturated; no surface water
02 / OVEN-DRY SOLIDS677.87 kg684.65 ÷ (1 + 1.00 / 100)
03 / WET BATCH MASS684.65 kg677.87 × (1 + 1.00 / 100)
MOISTURE ERROR EXPERIMENT / FROZEN BATCH TICKET
What if the stockpile is wetter than the ticket assumes?
Keep the ticket’s wet aggregate weights and mixer water unchanged. Change the actual moisture to see the resulting water and dry-solids errors. Recalculating the correction here would hide the error.
Ticket sand moisture 1.0%Stone 0.5%Mixer water 157.7 kg / ticket m³
Free-water error0.00 kg
Dry-solids error0.00 kg
Resulting w/b0.420 vs 0.420
Mass errors are per frozen ticket sized for 1 m³; its actual yield is unknown. Actual dry sand = 684.65 ÷ (1 + 1.0 / 100) = 677.87 kg. The binder mass stays fixed. Absorption demand is an SSD accounting assumption, not a model of absorption rate.
TRIAL NOTEBOOK / EVIDENCE FROM YOUR MATERIALS
Bring real batches back into the design.
Enter test results and actual batch quantities. Each record keeps its material identity, testing conditions and the current proposed design snapshot.
Checking browser storage…
Record a measured trial
All numbers below are measurements or user declarations. Default design values are not copied into measured fields. Keep one material series for the same constituent sources and proportions; start another when they change.
Identify the binder, aggregate and admixture family.
Supplier, lab report IDs and material dates.
Describe actual curing; different conditions plot separately.
Comma-separated measurements, e.g. three replicate values. The arithmetic mean is descriptive, not a code acceptance check.
Mixer + aggregate free moisture + admixture water + any later additions; exclude absorbed water.
Cement plus all cementitious additions, for that same physical batch.
Declare the intended volume of this physical trial batch. The current proposed design is 1.000 m³.
Measured density and yield · optional
Use the actual total mass charged to the batch and measured fresh density. Calculated volume closure does not establish actual yield. NRMCA CIP 8 ↗
Your observations will appear here.
No demonstration test results are prefilled. Record a batch to compare measured w/b and strength.
Design checks & assumptions 1
Absolute-volume closure: 1.000000 m³. Durability minimum: 300 kg/m³; maximum ratio: 0.50. These are selected checks, not a compliance certificate.
Admixture water contribution is set to 0%. Enter the supplier’s measured water fraction when applicable; do not assume a liquid product is water-free.
Strength reference readings, admixture reduction and material properties require trial verification. Sulphate exposure, chloride limits, constituent conformity and project-specific requirements need separate checks.
IS 10262:2019 ordinary/standard grade workflow · Selected IS 456:2000 durability provisions · Physical trials and project review required.
Concrete Ratio — M30 trial report
Engine 1.2.0; 1 m³; Moderate exposure; reinforced concrete. Preliminary trial only.
Inputs
- Concrete grade · characteristic strength (MPa)
- 30
- Exposure
- Moderate
- Concrete type
- reinforced
- Target slump (mm)
- 100
- Nominal maximum aggregate size (mm)
- 20
- Fine aggregate grading zone
- 2
- Coarse aggregate shape
- angular
- Cement reference strength band (MPa)
- 43 to <53
- Ratio selection method
- IS reference curve
- Entered trial water/binder ratio
- Derived from reference curve
- Standard deviation basis
- assumed
- Entered standard deviation (MPa)
- Assumed from grade and quality control
- Quality control
- good
- Designed batch volume (m³)
- 1
- Cement specific gravity
- 3.15
- Fine aggregate SSD specific gravity
- 2.65
- Coarse aggregate SSD specific gravity
- 2.74
- Entrapped air (% volume)
- 1
- Coarse aggregate volume-fraction reduction (%)
- 0
- Fly ash (% binder mass)
- 0
- GGBS (% binder mass)
- 0
- Silica fume (% binder mass)
- 0
- Fly ash specific gravity
- 2.2
- GGBS specific gravity
- 2.9
- Silica fume specific gravity
- 2.2
- Binder uplift (%)
- 0
- Credit SCMs toward minimum content
- No
- Water reduction (%)
- 20
- Admixture product (% binder mass)
- 1
- Admixture product specific gravity
- 1.145
- Water in admixture (% product mass)
- 0
- Fine aggregate absorption (% oven-dry mass)
- 1
- Coarse aggregate absorption (% oven-dry mass)
- 0.5
- Fine aggregate total moisture (% oven-dry mass)
- 1
- Coarse aggregate total moisture (% oven-dry mass)
- 0.5
- Specified free water (kg/m³)
- Table estimate
Materials to weigh
| Constituent | Per m³ · kg | Your 1 m³ batch · kg |
|---|---|---|
| Cement | 375.543 | 375.543 |
| Fine aggregate (as batched) | 684.646 | 684.646 |
| Coarse aggregate (as batched) | 1,236.877 | 1,236.877 |
| Water to add at mixer | 157.728 | 157.728 |
| Chemical admixture | 3.755 | 3.755 |
| Total batch mass | 2,458.550 | 2,458.550 |
Set the target mean strength
f′ck = max(fck + 1.65S, fck + X)
max(30 + 1.65 × 5.00, 30 + 6.50) = 38.25 MPa
Assumed standard deviation 5.00 MPa. The larger margin governs; characteristic and target strengths are different. (IS 10262:2019 · 4.2, Tables 1–2)
Select and check the water/binder ratio
r = min(strength-based ratio, durability limit)
min(0.42, 0.50) = 0.42
The ratio is interpolated from approximate Figure 1 readings and rounded down to 0.01. It is a preliminary selection, not a measured strength prediction. (IS 10262 · 5.1 / IS 456 · Table 5)
Estimate the free water
W = (W₀ − shape adjustment) × slump factor × (1 − reduction)
(186 − 0) × 1.060 × 0.80 = 157.7 kg/m³
The starting water estimate is for SSD aggregates. The 3% change per 25 mm slump and admixture reduction are preliminary; actual workability must be measured. (IS 10262 · 5.3, Table 4)
Calculate and allocate the binder
B = max((W ÷ r) × trial increase, durability minimum)
max((157.73 ÷ 0.42) × 1.00, 300.00) = 375.5 kg/m³
Final w/b is 0.420 after minimum-content or trial adjustments. Replacement percentages are fractions of total binder mass. (IS 10262 · 5.4 / IS 456 · Tables 5–6)
Close the absolute-volume balance
Vagg = 1 − Vair − Σ [mᵢ ÷ (Gᵢ × 1000)]
1 − 0.0100 − 0.2802 = 0.7098 m³
Use specific gravity, not loose bulk density. Water carried inside the chemical admixture is counted once, within that product’s volume. (IS 10262 · 5.2, 5.7)
Split the aggregate volume
pCA = [p₀ + 0.2(0.50 − w/b)] × (1 − reduction)
[0.62 + 0.2 × (0.50 − 0.420)] × 1.00 = 63.6% coarse / 36.4% fine
SSD masses: fine 684.6 kg and coarse 1236.9 kg per m³. The optional reduction is a trial adjustment up to 10%, not an automatic pumpability guarantee. (IS 10262 · 5.5, Table 5)
Correct for aggregate moisture
mOD = mSSD/(1+A); mwet = mOD(1+MC); Wsurface = mOD(MC−A); Wmixer = Wfree − Wsurface,sand − Wsurface,stone − Wadmixture
Sand surface water: 677.9 × (1−1)/100 = 0.00; stone surface water: 1230.7 × (0.5−0.5)/100 = 0.00; mixer water: 157.73 − (0.00) − (0.00) − 0.00 = 157.7 kg/m³ mixer water
All water quantities above are kg per m³. A and MC are fractions in the formula; entered percentages are divided by 100. Total moisture and absorption use an oven-dry mass basis. Surface water 0.0 kg plus admixture water 0.0 kg is deducted from the free-water budget. Negative surface water represents aggregate absorption demand. (SSD mass balance · IS 10262 Annexes A–B)
Scale and test the trial batch
Batch quantity = quantity per m³ × batch volume
Each constituent × 1.000 m³ = 1.000 m³ trial batch
Measure workability, fresh density, yield and strength; inspect segregation and bleeding. Revise the mix and record trials before project approval. (IS 10262 · 5.8)
Checks and assumptions
Admixture water contribution is set to 0%. Enter the supplier’s measured water fraction when applicable; do not assume a liquid product is water-free.
Verify applicable code editions, material tests and project requirements. Reference graph is approximate, not measured mix performance.
UNDERSTAND THE METHOD
A mix is designed.
Then it is proven.
A concrete grade describes characteristic strength. It does not define a fixed ingredient recipe. Mix design brings strength, workability and durability together using the materials actually available.
Concrete mix ratio guide: grade table, mass versus volume and worked quantities →
Begin with evidence
Specify grade, exposure and workability. Test constituent specific gravities, aggregate grading, absorption and moisture.
Balance water and binder
Choose a trial ratio from material evidence, check durability, estimate workability water and calculate the binder demand.
Account for every volume
Subtract paste and air from one cubic metre. Allocate the remainder to aggregates and correct the batch for moisture.
Close the loop with trials
Measure slump, density and strength. Inspect bleeding and segregation, adjust the design and repeat with the actual materials.
VOLUME ≠ MASS
One litre does not always weigh one kilogram.
Specific gravity connects mass to absolute volume. At a specific gravity of 3.15, 31.5 kg of cement occupies 10 litres of absolute solid volume. Loose powder also contains spaces between particles, so its bucket volume is different.
Method reference: IS 10262, clause 5.7WATER · SG 1.0010.0 kg
CEMENT · SG 3.1531.5 kg
AGGREGATE · SG 2.6526.5 kg
Equal absolute volume: 10 L each · illustrative specific gravities
MATERIAL SCIENCE
The details change the mix.
Small differences in the raw materials can change water demand, packing, workability and the measured strength.
Grading and particle shape
The aggregate skeleton controls how much paste is needed between particles. Grading zones, shape and surface texture inform a starting mix; a trial confirms its workability.
Fly ash, GGBS and silica fume
Supplementary materials change binder chemistry and particle packing. Their contribution depends on source, dosage and curing. A replacement percentage alone cannot establish strength or durability.
Water-reducing admixtures
Dosage and water reduction are separate inputs. Use supplier information and compatibility trials, and include water carried by liquid products in the water balance.
THE FINAL STEP IS PHYSICAL
A calculated strength is not a test result.
Keep specimen shape, test age, curing and test method consistent when comparing results. Indian M grades use characteristic cube strength; cylinder strengths and international class labels are not interchangeable.
Photo shows general laboratory cylinder testing, not an M-grade cube test. Xb-70 / Simpson Gumpertz & Heger, Inc. · Public domain.
THE STANDARDS BEHIND THE PROCESS
One method. Clear references.
This calculator implements the ordinary/standard grade IS workflow. Other regions are explained below as references; they are not interchangeable calculation modes.
IS 10262:2019
Concrete mix proportioning. Target strength, water, binder, air, aggregate allocation and trial procedure.
Read source text Third-party copy reviewed; © BIS. Verify the applicable edition and amendments through BIS.IS 456:2000
Selected exposure-based limits for water/cement ratio, minimum content and grade. Project requirements may be stricter.
View referenced provisionsMaterial evidence matters
IS 383: aggregates; IS 2386 Part 3: specific gravity and absorption; IS 9103: admixtures. Relevant parts of IS 1199 and IS 516 govern fresh and hardened testing.
Find applicable BIS standardsHow other regions approach concrete specification
United States
ACI PRC-211.1-22Mixture-proportioning guidance using absolute volumes. ACI structural requirements and applicable ASTM test methods have distinct roles.
ACI guideEurope & United Kingdom
EN 206 family / BS 8500Concrete specification, performance, production and conformity, with national provisions. Verify the locally adopted edition, including the 2026 EN 206 revisions.
BSI referenceCanada
CSA A23.1 / A23.2Materials, construction and testing requirements. Exposure classes and test conventions need their own implementation.
CSA GroupAustralia
AS 1379 / AS 1012 familyConcrete specification and supply, and concrete test methods. These references do not convert an Indian trial into an Australian-compliant mix.
Standards AustraliaSpecial mixes—self-compacting, mass, fibre-reinforced, lightweight and M65+ high-strength concrete—need additional methods and tests. The present calculator does not certify those designs.
A FEW IMPORTANT DISTINCTIONS
Understand the answer.
How do I calculate an M20 or M30 concrete mix ratio?
Select M20 or M30 in the grade grid and enter your required concrete volume. The calculator estimates binder, sand, stone and water from the design brief and material properties. Review exposure, moisture and the calculation steps before making a physical trial. The displayed proportion is specific to those inputs.
How much cement, sand and aggregate do I need for 1 m³?
Set the concrete quantity to 1 m³. The To weigh view shows each ingredient in kilograms, including moisture-corrected sand and stone and the water to add at the mixer. Change the quantity to scale the same design. The In the mix view shows absolute-volume contributions in litres, not loose bucket quantities.
Why is the target strength higher than the grade?
The grade describes characteristic strength. Mix proportioning uses a higher mean target to allow for variation. The IS 10262 method checks both the statistical margin and the grade-based minimum margin.
Can I use one fixed ratio for M25, M45 or M50?
No universal ingredient proportion establishes these grades. Strength, exposure, workability and actual material properties determine a trial mix. The calculated ratio shown here changes with your inputs.
Does a lower water-cement ratio always solve the design?
A lower ratio can support higher strength for a given material system, but the concrete must still be workable, placed, compacted and cured properly. A graph cannot account for every production condition.
Why do moisture corrections change water and aggregate weights?
The SSD design includes water absorbed inside aggregates. Actual stockpiles may be wetter or drier. Correcting both aggregate mass and added water preserves the intended solids and free-water balance.
Is this a code-approved mix design?
No. It is a transparent preliminary proportioning and learning tool. The selected code provisions do not replace material conformity checks, physical trials, acceptance testing or project-specific professional approval.