STRENGTH
Concrete strength classes
Understand the Cxx/yy notation and why class alone cannot determine constituent quantities.
Explore classes →EUROPE · CONCRETE SPECIFICATION CONTEXT
Explore the mixture without pretending Europe has one universal recipe.
EN 206 provides a concrete specification, performance, production and conformity framework. This site uses strength, exposure and constituent inputs to build a transparent preliminary mixture, while keeping national provisions and project-specific requirements outside the calculator where they belong.
EN 206 contextStrength, exposure, constituent limitations, production and conformity are treated as a specification framework—not a universal mix recipe.
National provisions matterCountry-specific rules can alter or supplement what is required for an actual project.
Transparent starting mixSee how the preliminary constituent quantities are assembled instead of relying on a fixed ratio.
Field verificationMaterial data, production controls and trial evidence remain essential before construction use.
2026 TRANSITION
EN 206 has moved into a new generation
EN 206-1:2026 was published in March 2026 and supersedes the previous EN 206:2013+A2:2021 framework at European level. National publication, transition and contractual adoption can differ, so always check the standard actually in force for the project location.
| Layer | What it controls | How to treat it here |
|---|---|---|
| EN 206-1:2026 | European concrete performance, requirements, factory production control and assessment framework | Use the site to understand the concepts; verify the official document for binding requirements |
| National standard/provisions | Country-specific application, complementary requirements and accepted constituent combinations | Do not transfer limits from one country into another without verification |
| Project specification | Concrete actually required for the structure | Use project strength, exposure, consistence and material requirements as inputs |
| Producer / trials | Demonstrates that the actual constituents and production process meet the specification | Treat calculator quantities as a preliminary starting point only |
CLASSES & EXPOSURE
C25/30 is a strength class—not a complete mixture specification
The paired cylinder/cube class is one part of the concrete description. Exposure, consistence, maximum aggregate size, chloride class, constituent rules and national provisions can all affect the specified concrete.
EXPOSURE
Exposure & durability
See why environmental actions change composition limits and verification requirements.
Read guide →METHOD
Preliminary proportioning
Follow the educational calculation path without confusing it with an EN 206 conformity procedure.
See method →FIELD CONTROL
A compliant specification still needs controlled production
Moisture correctionTrack water carried by aggregate so the intended free-water balance is not lost.
Mixture stabilityRecognise when handling, grading or excess water causes the fresh mixture to separate.
CuringProtect early-age conditions after placement; design strength alone does not guarantee durable concrete.TOOLS
Use the numbers with their engineering context
CALCULATOR
Preliminary mixture calculator
Explore a transparent constituent balance using selected strength and exposure inputs.
Open calculator →GUIDES
European reference guides
Read about classes, exposure and specification before using values in a project context.
Browse guides →COST
Material cost
Apply your own rates to the preliminary material quantities.
Estimate cost →CARBON
Carbon estimate
Explore the influence of constituent quantities with project-appropriate factors.
Estimate carbon →TRIALS
Trial batches
Measure fresh behaviour, yield and strength before considering a preliminary mixture ready for production.
Read guide →SITE PRACTICE
Concrete field library
Continue into slump, vibration, segregation, formwork, honeycombing and curing.
Open library →IMPORTANT LIMIT
This site cannot tell you that a mix “complies with EN 206” from proportions alone.
EN 206 conformity involves specification, production control, assessment and national application—not merely a cement, water and aggregate calculation.
- Identify the national version and provisions applicable at the project location.
- Confirm the contract/specification and permitted constituent combinations.
- Use real material and production data.
- Follow the required conformity and acceptance procedures.