Tool for quick thermal analysis of assemblies
Concrete slab volume calculator
Concrete slab volume calculator for patios, floors, and simple slabs. Calculate volume, add waste, and use a worked example.
Working calculator
Enter the core dimensions and check the result directly on this page.
A 6 m by 4 m slab at 150 mm thickness
U-value
What this example represents
This variant describes an assembly related to a concrete wall. The page focuses on material, thickness, and the resulting U-value. Read the value as a conceptual comparison: it shows the effect of thickness and lambda, but it does not include every junction detail, fixing, or moisture condition.
The insulation material or assumption is an insulation layer. If there is no additional insulation, the result mainly shows the limits of the structural layer itself.
Dense concrete usually needs a clear insulation layer because its own thermal resistance is limited. Before using the result for construction decisions, check current product data, local requirements, layer continuity, and possible thermal bridges.
Compare this page with nearby variants rather than reading it in isolation. The most useful set is the no-additional-layer case, a minimum option, and an option with margin for installation error and material tolerance.
If the example covers services, concrete, or heating, use it as a starting point for range checking. Exact sizing still depends on standards, loads, pressures, protective devices, or local execution conditions.
Concrete slab volume calculator
Concrete slab volume calculator
Concrete slab volume calculator for patios, floors, and simple slabs. Calculate volume, add waste, and use a worked example.
Assembly thickness
Assembly thickness
Concrete slab volume calculator for patios, floors, and simple slabs. Calculate volume, add waste, and use a worked example.
U-value
U-value
Concrete slab volume calculator for patios, floors, and simple slabs. Calculate volume, add waste, and use a worked example.
CategoryLambdaLayerMaterialThickness
How it works
Is the calculator suitable for quick design checks?
Focused thermal conductivity and U-value tools, guides, and comparison pages.
Can I switch thickness units?
Focused thermal conductivity and U-value tools, guides, and comparison pages.
Concrete slab volume calculator
Concrete slab volume calculator for patios, floors, and simple slabs. Calculate volume, add waste, and use a worked example.
Concrete slab volume calculator for patios, floors, and simple slabs. Calculate volume, add waste, and use a worked example.
Add layerRestore default setupRemove
Assembly nameThickness unitInternal Rsi (m2K/W)External Rse (m2K/W)
Calculation assumptions
The calculators use visible formulas and explicit unit conversions. Treat the result as a preliminary check, not a complete building design.
- SI and US units are converted separately; R, RSI, U-value, and U-factor are not mixed without the unit factor.
- Enter positive values and compare the result with the selected product datasheet.
- Local codes, thermal bridges, fasteners, and installation quality can change the requirement.
- Last formula review: 2026-04-27.
See how formulas, unit conversions, rounding, and limitations are handled. Methodology details.
Frequently Asked Questions
Lambda is the thermal conductivity of a material, usually shown in W/mK. Lower lambda means heat moves through that material more slowly, but the final assembly still depends on thickness, surface resistances, and every other layer.
U-value describes heat loss through the whole building element, not just one material. A low U-value usually means a better insulated wall, roof, or floor, provided the real build-up matches the layers entered in the calculator.
Yes. Use the comparison section to keep thickness constant, then compare materials by lambda and calculated thermal resistance. This is useful when two products look similar on paper but behave differently at the same installed depth.
Yes. You can print the result or export it to CSV, Excel, or PDF for reports and documentation.
Yes. It is designed for layered assemblies such as external walls, flat roofs, pitched roofs, floors, and slabs. For unusual assemblies, add every relevant layer and treat the result as a planning check before formal verification.
Yes. It is intended for fast concept-stage calculations, insulation comparison, and envelope optimisation before detailed design. It is best used to narrow choices, not to replace a code check or project-specific thermal bridge assessment.
Yes. You can switch between millimeters, centimeters, and inches, and the calculator keeps the values consistent. For fewer mistakes, choose one unit system at the start of a project and review converted thicknesses before export.
Use Concrete slab volume calculator as a first-pass reference. Before specifying anything, compare the result with the reinforcement, actual project dimensions, product data sheet, and local requirements.