BS 8500 & Eurocode 2 compliant mix design, exposure class, steel, screed, insulation, masonry, drainage, and cost calculators — free for UK construction professionals and self-builders.
Calculate how much concrete you need and get an instant 2026 UK ready-mix cost estimate. Enter your pour dimensions below — results appear instantly.
For a full mix design with BS 8500 compliance checks, exposure class selection, reinforcement cover, and site-mix quantities — use the RC30/37 Concrete Calculator or the Full Mix Design Tool.
MixDesignCalc.co.uk is the UK's most comprehensive free construction calculator library, covering concrete mix design, steel reinforcement, masonry, screed, insulation, drainage, and project cost estimation. Every concrete calculator references BS 8500-1:2015+A2:2019 and BS EN 206:2013+A2:2021, with Eurocode 2 (BS EN 1992-1-1) cover calculations, exposure class compliance checks, and 2026 UK regional pricing built in.
All concrete calculators automatically check your specification against BS 8500-1 Table A.1 limiting values — maximum w/c ratio, minimum cement content, minimum strength class, and nominal cover — for your selected exposure class.
Nominal cover (cnom = cmin + Δcdev) is calculated to EC2 for every reinforced concrete application, with automatic structural class adjustment and 25/50/100 year design life options.
All calculators include 2026 UK regional price estimates — South East England, London, Midlands, North England, Scotland, and Northern Ireland — updated annually from market data.
Every calculator runs client-side in your browser — no login, no registration, no data collection. Results appear instantly. Use on any device, any time, on or off site.
From XC1 (dry interior) through XD3 (de-icing salt) and XS3 (marine tidal zone) — every BS EN 206 / BS 8500 exposure class has a dedicated calculator with full compliance checking.
Every calculator on MixDesignCalc.co.uk is completely free to use. No subscriptions, no per-use charges, no paywall. The full library — 200+ tools — is free to every UK construction professional.
MixDesignCalc.co.uk is a specialist UK construction calculator resource built for civil and structural engineers, contractors, quantity surveyors, building surveyors, and self-builders. The site provides over 200 free technical calculators covering every aspect of UK construction practice — from BS 8500 concrete mix design through Eurocode 2 reinforced concrete design, to BS 4483 steel mesh, cavity wall blockwork, anhydrite and self-levelling screeds, XPS and PIR insulation, BRE 365 soakaway design, and 2026 UK regional construction cost estimation.
Every concrete mix design calculator implements the BS 8500-1:2015+A2:2019 Table A.1 limiting values correctly for each exposure class — maximum w/c ratio, minimum cement content, minimum strength class, and nominal cover — automatically flagging any non-compliance. Nominal cover calculations use the Eurocode 2 method (cnom = cmin + Δcdev) with structural class adjustment for design working life and concrete grade. Steel mesh calculators reference BS 4483:2005 and BS 4449 Grade B500B properties. Soakaway design follows the BRE Digest 365 method with soil infiltration rate testing guidance.
| Standard | Title | Used In |
|---|---|---|
| BS 8500-1:2015+A2:2019 | Concrete – Method of specifying (UK complement to BS EN 206) | All concrete mix design & exposure class calculators |
| BS EN 206:2013+A2:2021 | Concrete – Specification, performance, production, conformity | All concrete calculators |
| BS EN 1992-1-1 (EC2) | Eurocode 2 – Design of concrete structures | All RC calculators with cover and crack width |
| BS 4483:2005 | Steel fabric for reinforcement of concrete | A142, A193, A252, A393, B & C mesh calculators |
| BRE Digest 365 | Soakaway Design | Soakaway Size Calculator |
| Approved Document H | Building Regs – Drainage and Waste Disposal | Soakaway, drainage calculators |
| Approved Document L 2021 | Building Regs – Conservation of Fuel and Power | XPS, EPS, PIR insulation calculators |
| BS 3882:2015 | Specification for topsoil | Topsoil Calculator |
| BS EN 771-1, 771-3 | Specification for masonry units (clay & concrete) | Brick and block calculators |
Yes — every single calculator on MixDesignCalc.co.uk is completely free to use, with no registration, no subscription, and no per-use charge. The entire library of 200+ tools is free and accessible to all UK construction professionals, students, and self-builders. There is no paywall, premium tier, or hidden charge of any kind.
For a standard domestic reinforced concrete ground floor slab for a house extension, use the RC30/37 Concrete Calculator. Select exposure class XC3 (for an internally insulated slab) or XC4 (if any part of the slab face is exposed externally), Structural Class S4, and 50-year design life. The standard UK domestic floor slab specification is RC30 (C30/37) at 150mm thickness with A142 or A193 steel mesh reinforcement and 35mm (XC3) or 40mm (XC4) nominal cover. Always follow your structural engineer's specification.
There is no difference — RC30 and C30/37 describe exactly the same concrete. RC30 is the BS 8500 designated mix notation used when ordering from a ready-mix supplier. C30/37 is the strength class notation from BS EN 206 and Eurocode 2 used in structural design documents. When a structural engineer writes C30/37 on a drawing, the contractor orders RC30 — they are the same product.
Each exposure class calculator (XC1 through XC4, XD1 through XD3, XS1 through XS3, XF1 through XF4) implements the BS 8500-1:2015+A2:2019 Table A.1 limiting values for that specific class. When you enter your pour dimensions, cement type, target strength, and design life, the calculator checks your specification against the standard's maximum w/c ratio, minimum cement content, minimum strength class, and minimum nominal cover, displaying a colour-coded compliance result. The EC2 nominal cover (cnom = cmin + Δcdev) is calculated automatically, adjusted for structural class and design life.
All 2026 price estimates are based on typical UK market rates at the time of publication and provide a useful ballpark for budgeting and checking contractor quotes. Actual prices vary between suppliers, locations, and change with market conditions — particularly ready-mix concrete prices, which are linked to cement and fuel costs. Always obtain at least two competitive quotes from local suppliers before ordering. The price calculators show indicative ranges, not fixed prices, and some calculators allow regional selection to reflect the significant geographic variation in UK construction costs.
Absolutely — new calculator requests from users are one of the main ways we decide what to build next. Use the Contact Us page, select "Suggest a new calculator", and describe the calculation you need. Include the relevant UK standard or design code if you know it, the inputs you would need to enter, and the outputs you need. Popular suggestions with a clear UK standards basis are typically implemented within 4–8 weeks.
MixDesignCalc.co.uk calculators provide technically correct indicative guidance based on current UK standards, but they are not a substitute for a formal structural engineer's specification or a concrete producer's BS EN 206 mix design certificate. For Building Regulations submissions, all structural concrete specifications must be confirmed by a qualified Chartered Structural Engineer (MIStructE or CEng) and backed by conformity test data from a BS EN 206-compliant ready-mix producer. The calculators are most appropriately used for preliminary design, cost estimation, compliance checking, and education.
Use the Quick Concrete Calculator above on this page: enter your slab dimensions (length, width, and depth in metres), select your concrete grade, and choose your UK region. The calculator will give you the net volume, the volume to order with 10% wastage, and an estimated 2026 ready-mix cost. For a full mix design with BS 8500 compliance checking, use the RC30/37 Concrete Calculator. A typical domestic floor slab at 150mm depth: 6m × 4m = 24 m² × 0.15m = 3.6 m³ net; order approximately 4.0 m³ with 10% wastage.
Key UK construction standards and organisations: The Concrete Centre | The Concrete Society | BSI Group | IStructE | NHBC Standards | Planning Portal | Building Regulations Approved Documents | Contact Us