The trusted reference for engineers, contractors, students, and self-builders worldwide. Estimate mix design, quantities, costs, and more — instantly, for free, on any device.
Quick Guides — No Setup Required
Our most popular resources — ready to use instantly. Select a guide below and get results in seconds.
Every Free Guide — by Category
Browse all our resources and guides — from concrete volume guides to IS 456 standards references. All free, all instant, all on one site.
Concrete Volume Guides
Estimate exact concrete volumes in m³, weight in kg and tonnes, and ready-mix order quantities for every standard structural element type.
Concrete Mix Design Resources
Design and proportion your concrete mix using IS 10262:2019 and ACI 211.1 methods. Estimate cement, sand, aggregate, and water for any grade.
Quantity & Material Guides
Estimate every material needed for your project — cement bags, fine and coarse aggregate, steel reinforcement, and complete construction quantities.
Cost & Budget Planners
Plan your complete construction budget — from land and foundation to finishing and contingency. Track every cost category with instant totals.
Unit Conversion guides
Convert between metric and imperial units for length, area, volume, and weight — essential for engineers working across UK, US, and Indian standards.
Standards & Code Guides
Complete reference guides to the world’s major concrete design codes — IS 456, ACI 318, BS EN 1992 (Eurocode 2), and ASTM standards.
Construction Guides
Step-by-step construction guides written by qualified engineers — from beginners’ introductions to advanced formwork, reinforcement, and curing procedures.
Formulas & Reference Charts
Complete formula libraries for concrete volume, strength, mix ratios, development length, and structural design — with worked examples and code references.
Resources & Reports
Additional productivity resources for engineers and contractors — PDF report generator, project planner, and all-in-one resource hub.
Jump to Any Guide
All resources — one click away
Concrete Volume
Any element, instant m³
Mix Design
IS 10262 & ACI 211
Footing
Pad, strip & combined
Slab
Floor & roof slabs
Aggregate
Gravel, sand & stone
Cement Bags
How many bags per m³
Budget Planner
Land to finishing
Qty Guide
All materials, all elements
w/c Ratio
Check IS 456 compliance
Unit Conversion guide
m↔ft, kg↔lb, m³↔ft³
Built for Engineers, Used by Everyone
What makes concretesmath.com/ the trusted first choice for construction estimates across more than 50 countries.
Engineering-Grade Accuracy
Every formula is sourced from IS 456:2000, IS 10262:2019, ACI 318-19, BS EN 1992-1-1, and NHBC Standards — not simplified approximations. The same formulas used in professional structural engineering software, free. For related background, see About Us.
100% Private — No Data Sent
All estimates happen entirely in your browser — nothing is ever sent to our servers. Your project dimensions, mix designs, and budget figures stay completely private. No sign-up, no email required.
Designed for Real Jobsites
Always Up to Date
Every guide and guide is reviewed and updated annually. IS 10262:2019 (not 1982), ACI 318-19, 2026 material densities, and current code references — never outdated information from abandoned sites.
Covers All Major Standards
IS 456 for South Asia, ACI 318 for the Americas and Middle East, and BS EN 1992 (Eurocode 2) for the UK and Europe — all on one site, with comparison tables and cross-referenced grade equivalents.
Learn While You Estimate
Every guide comes with complete guides, worked examples, reference tables, and FAQ — so you understand the results, not just copy numbers. Built for students and professionals alike.
Every Formula Has a Source — We Cite It
Unlike most concrete guides, we show you where every formula, density value, and code requirement comes from. You can verify everything we estimate.
IS 456:2000
Indian Standard for Plain & Reinforced Concrete — design, materials, mix, cover, reinforcement, and acceptance.
IS 10262:2019
Indian Standard for Concrete Mix Design Proportioning — current edition used in all our mix design estimates.
ACI 318-19
Building Code Requirements for Structural Concrete — primary US international standard for concrete design.
ACI 211.1-91
Standard Practice for Selecting Proportions for Normal-Weight Concrete — basis of ACI mix design.
BS EN 1992-1-1 (EC2)
Eurocode 2 — Design of Concrete Structures. Referenced in our exposure class and grade comparison tables.
NHBC Standards
UK residential foundation requirements — referenced in our strip footing minimum sizes and domestic guidance.
BS EN 1991-1-1 (EC1)
Source of the 2,400 kg/m³ reinforced concrete density used in all our weight estimates.
ASTM C150, C31, C39
US standards for Portland cement, concrete specimen preparation, and compressive strength testing.
Trusted by Engineers & Builders Worldwide
Real feedback from the engineers, contractors, students, and self-builders who use concretesmath.com/ every day.
“I have been a structural engineer for over 15 years and this is genuinely the best free concrete resource online. The IS 456 guide is comprehensive — I use it to double-check my design estimates and to answer client questions on site. The mix design guide follows IS 10262:2019 correctly, which almost no other site does.”
"We use the Budget Planner and Quantity Guide on every new residential project. Before finding concretesmath.com/, I was doing all of this in Excel — now my site engineer does it on his phone during the site visit. The results are accurate and the breakdown by element type makes it easy to check against our BOQ."
“Studying civil engineering and this site has been a lifesaver for understanding IS 456. The explanations alongside the guides are better than my textbooks — they explain the ‘why’ behind the formulas, not just give you an answer. The beginners’ guide to concrete was the first resource that made mix design actually make sense.”
“As a self-builder in the UK, I needed reliable resources to double-check what my contractor was telling me. The footing guide gave me the exact concrete volumes — it matched my contractor’s figure almost exactly. The privacy policy confirmed no data is collected, which matters when I’m entering project dimensions.”
“The ACI 318 standards guide is excellent. I work on World Bank projects in South Asia where we need to translate between IS 456 and ACI specifications — the comparison table in the IS 456 guide is the clearest side-by-side comparison I have found anywhere online. Bookmarked and shared with my entire team.”
“The slab construction guide has become our site supervisor’s go-to reference. The pre-pour checklist is particularly useful — we print it out for every slab pour. It has prevented several errors on site, including once when our subcontractor had placed top bars at the wrong depth. Worth its weight in gold.”
Essential Concrete Facts Every Builder Should Know
Quick reference facts drawn from IS 456:2000, ACI 318-19, and established concrete technology — all in one place.
Frequently Asked Questions
Quick answers to the most common questions about our guides, methods, and the site itself.
Are all the guides on concretesmath.com/ completely free?
Yes — every guide, guide, reference table, and resource on concretesmath.com/ is 100% free, with no limits on how many times you use them and no requirement to create an account or provide your email address. We have never charged for access and never intend to. Our mission is to make professional-quality engineering resources available to everyone.
Which concrete standards do the guides follow?
Our guides reference IS 456:2000 (India/South Asia), IS 10262:2019 (Indian mix design), ACI 318-19 (USA/International), ACI 211.1-91 (ACI mix design), BS EN 1992-1-1 Eurocode 2 (UK/Europe), BS EN 1991-1-1 (concrete density), NHBC Standards (UK domestic foundations), and ASTM standards for material testing. Every formula is cited with its source — you can verify any result against the original code. For related background, see ACI Standards.
How do I estimate how much concrete I need for a slab?
How many cement bags are needed per m³ of M20 concrete?
For M20 concrete using IS 456 nominal mix (1:1.5:3): cement content = 383 kg/m³. Using 50kg bags: 383 ÷ 50 = 7.66 → round up to 8 bags per m³. With 10% wastage, order 9 bags per m³. You also need approximately 574 kg of fine aggregate (sand) and 1,147 kg of coarse aggregate per m³. Use the Cement Bags Guide or Quick Guide above for any grade and volume.
What is the mix ratio for M20 concrete?
The IS 456 nominal mix ratio for M20 concrete is 1:1.5:3 (Cement : Fine Aggregate : Coarse Aggregate by volume). This is the most widely used concrete grade in residential construction in India and Pakistan. For a designed mix per IS 10262:2019 with 20mm aggregate and Zone II sand, the ratio by mass is approximately 1:1.50:2.99 — similar but optimised for your specific materials. Use our Mix Design Guide for a full designed mix estimate.
Does concretesmath.com/ collect my project data or estimate inputs?
No — all estimates are performed entirely within your browser using JavaScript. Your project dimensions, concrete volumes, mix designs, and budget figures are never transmitted to our servers and are not stored anywhere. When you close or refresh the page, the data disappears. This is confirmed in our Privacy Policy. You can safely use our resources for confidential commercial or client projects.
Can I use these guides for commercial or professional projects?
Yes — our resources are used by structural engineers, quantity surveyors, site managers, and contractors on live commercial projects daily. However, as stated in our Disclaimer, all results should be verified by a qualified structural engineer before use in structural design. Our guides are accurate reference and estimation resources — they do not replace a structural engineer’s judgment, site-specific assessment, or formal design estimates for critical elements.
Which countries is concretesmath.com/ designed for?
Our resources and guides cover all major construction markets: India and Pakistan (IS 456, IS 10262), the United Kingdom (BS EN 1992 / Eurocode 2, NHBC), the United States (ACI 318, ACI 211, ASTM), and other countries that use these codes including Bangladesh, Sri Lanka, Nepal, UAE, Saudi Arabia, Australia, and South Africa. Grade conversion tables allow engineers to translate between code systems when working across international projects.
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