METHOD & TRANSPARENCY

Know what the tool calculates.

Concrete Ratio is an independent educational and preliminary concrete mix proportioning workspace. It makes inputs, assumptions, intermediate equations and trial quantities visible.

Country and calculation scope

Country detection suggests a workspace on the home page. The Indian worksheet uses the IS engine described below. The US worksheet uses ACI-family absolute-volume arithmetic with dry-rodded coarse aggregate; the UK worksheet uses BS/EN strength classes and user-qualified water and aggregate inputs. A general project worksheet is available elsewhere. Explicit regional pages and your saved project preference take precedence over location. A transferred Indian mix stays in the IS engine.

The US and UK worksheets do not implement all ACI selection tables, the full BRE design method, or complete national-code conformity checks. They show source references, user-supplied constraints, visible dimensional calculations and moisture-corrected trial quantities. Cylinder and cube requirements remain distinct. Actual project specifications and trial testing govern.

Indian IS engine

The engine implements the ordinary and standard grade workflow of IS 10262:2019 for normal-weight, non-air-entrained concrete, from M10 through M60. Selected IS 456:2000 durability checks are included. It is not BIS software, a conformity certificate, or a project-approved mix design.

The base cement is ordinary Portland cement (OPC), with separate inputs for supplementary cementitious additions. Factory-blended and Portland calcined-clay limestone cements are not separate supported modes. Their cement-specific provisions need an additional assessment.

• Target mean strength uses the greater of the statistical and grade-based margins.
• Water estimates, binder quantities, aggregate fractions and moisture corrections use a consistent SI mass and absolute-volume basis.
• The interactive reference graph is an approximate manual redraw of Figure 1. It is not a digital table published by BIS or a measurement of your concrete.
• SCM blends require material-specific ratio inputs; OPC curves are not automatically applied to them. Without established SCM durability credit, both minimum content and the durability water ratio use OPC alone. Replacement limits, including IS 456 Amendment 6 (2024), need separate review.
• Special concrete families and full structural, sulphate, chloride and acceptance checks are outside this implementation.

Country suggestion and privacy

When no project preference or explicit regional page applies, the home page makes one request to Country.is for your approximate IP country. That service receives your IP address as part of the request. We retain only the returned country code for the browser session; we do not retain the IP address, request coordinates, or ask for device/GPS location. Requests omit cookies and the referring page.

A manual country choice is saved locally in your browser. The “Use my location” link clears that preference and requests a new suggestion. VPNs and network routing can make IP country inaccurate. If detection fails, the general project worksheet remains available. Location never establishes which standard a construction project must follow.

How to read the batch summary

Required volume is stored in cubic metres; 1 m³ is 1,000 litres. Total batch weight sums the calculated ingredient masses. The To weigh view uses moisture-corrected aggregate weights and water to add at the mixer. The In the mix view shows absolute-volume contributions with saturated surface-dry aggregates, admixture and air. These volumes are not loose bucket measurements. Displayed values are rounded; exports provide additional precision.

Designed volume is not measured yield. Actual batch yield requires measured fresh density and actual batched masses, as explained in NRMCA CIP 8.

Graph-driven aggregate design

The Graph design workspace combines sand and stone sieve curves by oven-dry mass. You can drag a target curve, fit a blend share and preview batch quantities before applying it. Example curves are illustrative; user-entered values are not independently verified. The fit minimizes squared differences across the displayed sieves, not concrete cost, packing density or strength.

An applied graph blend replaces the IS table aggregate split. Its dry-mass share is converted using absorption and bulk SSD specific gravity before absolute-volume proportioning. The source sieve values and target are included in exports. No IS 383 grading-envelope conformity is inferred from the graph.

Experiment and measurement workbenches

Experiment mode keeps free water or binder fixed while exploring the requested water/binder ratio. Governing limits remain visible; candidates that fail an action-level check cannot be applied from the experiment panel. The IS trial planner varies the pinned ratio by about ±10% at a fixed revised water budget. Specified free water bypasses the table estimate.

The moisture-error experiment freezes wet batch weights and mixer water to expose errors caused by incorrect stockpile moisture. The trial notebook stores user-entered measurements, including specimen geometry, curing, age and actual batch water/binder. Its points and replicate ranges are descriptive, not predictions or acceptance assessments. Measured yield uses actual batch mass divided by measured fresh density.

Read the comparative research and implementation decisions.

Sources and review

The numerical method was checked against the referenced 2019 and 2000 source texts. Current amendments and project requirements must be verified through the Bureau of Indian Standards before project use. No independent professional certification is claimed.

IS 10262:2019 source copy · IS 456:2000 source copy. These are third-party copies of BIS documents; no full standard is redistributed by this website.

Your inputs

Connected-tool links carry the selected design inputs in the URL fragment, after the # character. Anyone receiving that complete link can read those assumptions, and it may remain in browser history. Material prices stay in the cost-calculator page session and are not included in mix-transfer links. CSV downloads include the values you choose to export.

Main calculator inputs and pinned experiments are held in the current page session. Measured trial records, material references and design snapshots are saved in this browser’s local storage when available. They are not synchronized across devices. Clearing site data removes them; export a JSON backup before doing so. JSON import restores compatible notebooks, and CSV exports measurements. The application does not send your design or trial records to an application database or an AI service. Worksheet exports and printing run in your browser.

The hosting provider may process ordinary request and access logs. This version does not include third-party analytics or an AdSense script.

Advertising

There are no active ads in this version. Future advertising positions are planned after explanatory content, separate from input controls, graph interactions and export buttons. Activation requires publisher setup and an updated privacy and consent implementation appropriate to the audience.

Checking a result

For reproducible checking, retain the exported worksheet, input values, calculation step number and expected value with its source. Compare the result with independent calculations and material trial results before use.

Image credits

The sand-weighing scene in the aggregate moisture correction guide is an original OpenAI-generated illustration. It shows the concept of weighing aggregate samples, not a documented test or a complete laboratory procedure.

The ingredient samples and aggregate-moisture cutaways in the visual guide are original AI-generated educational illustrations created with OpenAI image generation. Their labels and worked example are typeset separately. Sample sizes are not mix proportions; pores are exaggerated to explain moisture states. These illustrations are not laboratory photographs or test results. Live composition charts use calculated quantities, independently of the illustrations.

Aggregate photograph: Bill Bradley/Billbeee, CC BY 3.0; cropped for display. Laboratory testing photograph: Xb-70, courtesy of Simpson Gumpertz & Heger, Inc., public domain; cropped for display.

Research and implementation updated: 6 September 2026.