Watson
West Midlands
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Opening Hours:
Monday - Friday 8am - 7pm
Saturday : 9am - 6pm
Precision Concrete Calculator –
Estimate Bags, Cubic Meters & Cost for Your Project (UK 2025)
Instantly calculate how much ready-mix concrete, cement, or ballast you need for slabs, footings, and foundations – with cost estimates for UK suppliers like CEMEX and EasyMix.
Accurate Concrete Estimates in Seconds
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Shape-Specific Calculations: Slabs, footings, columns, curbs
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UK Supplier Pricing: Compare costs for CEMEX, Heidelberg, Rapid Readymix
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Bag vs. Bulk: Convert between cubic meters and 20kg/25kg bags
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4:2:1 Mix Ratio: Auto-calculates cement, sand, and aggregate
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Waste Buffer: Optional 5-10% overage for spillage
How It Works
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Enter Dimensions: Length × Width × Thickness
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Select Mix Ratio: Standard (1:2:4) or custom
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Get Results: Volume, bags, cost, and material breakdown
Concrete Calculator:
FAQ Section
Q: How many 20kg bags make 1m³ of concrete?
*A: ~80 bags (1m³ = 1,000kg ÷ 20kg = 50 bags cement + 30 bags ballast for 1:2:4 mix).*
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Q: What’s the 4:2:1 concrete rule?
*A: 4 parts ballast : 2 parts sand : 1 part cement – our calculator auto-adjusts ratios.*
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Q: How much is concrete per m² in the UK?
*A: £65-£100/m² (thickness-dependent). For 100mm slab: 0.1m³/m² × £120/m³ = ~£12/m².*
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Q: Can I calculate cost for CEMEX or EasyMix?
A: Yes! Select "Supplier Quotes" to compare local ready-mix prices.
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Q: How thick should a driveway slab be?
*A: 100-150mm for cars, 150-200mm for heavy vehicles (use "Driveway" preset in calculator).*
