About the Embodied Carbon Calculator
The Embodied Carbon of Building Materials Calculator estimates the manufacturing related CO2 emissions locked into a quantity of a common construction material, such as concrete, steel, timber, brick, or aluminum. It is aimed at anyone comparing material choices during design or renovation who wants a rough carbon figure to weigh alongside cost and performance. The output is expressed in both kilograms and metric tons of CO2 equivalent.
How It Works
You select a material from a short list and enter the quantity in kilograms. The calculator looks up a fixed embodied carbon factor, in kilograms of CO2 equivalent per kilogram of material, for the selected material and multiplies it by your quantity to get total embodied carbon. The result is shown in both kilograms and metric tons alongside the factor used, so you can see which coefficient drove the number.
Formula & Methodology
These per kilogram factors come from published cradle to gate embodied carbon coefficients, drawn from sources like the Inventory of Carbon and Energy database, meaning they cover raw material extraction, processing, and manufacturing up to the factory gate. To estimate a full project's total, you would run this calculation separately for each material and quantity used, then add the results together.
Examples
Small Concrete Pour
For a 2,500 kg concrete pour, roughly a small footing or slab section, the calculator returns about 267.5 kg CO2e, or roughly 0.27 metric tons, using the 0.107 kg CO2e per kg concrete factor.
Structural Steel Comparison
For 800 kg of virgin structural steel, the result comes to about 1,528 kg CO2e, or roughly 1.53 metric tons, using the 1.91 kg CO2e per kg steel factor, more than five times the concrete example despite less than a third of the mass.
Advantages
- Lets you directly compare the embodied carbon of different structural material choices using the same published coefficients.
- Converts a vague greener material claim into a specific kilogram or ton figure tied to actual project quantities.
- Useful early in design, before detailed specifications are finalized, to sanity check material carbon impact by weight alone.
Common Mistakes
- Treating the result as a complete project carbon footprint when it covers only one material's manufacturing emissions, not transport, installation, or the rest of the building.
- Assuming timber's low factor already accounts for its carbon sequestration benefit, when the figure reflects processing emissions only.
- Comparing materials by volume, like cubic meters of concrete versus lumber, without first converting to the kilogram quantities the calculator actually requires.
Edge Cases to Watch For
- The factors cover extraction, processing, and manufacturing only. They exclude transport to the job site, on site installation energy, and end of life disposal, so a full project's true footprint would run higher than this figure alone.
- Timber's factor doesn't subtract the carbon a tree sequestered while growing, so the number reflects processing emissions only, not any net carbon benefit from that sequestration.
- Selecting steel (virgin) or aluminum (virgin) assumes primary, non recycled material. Recycled content in either metal would carry a substantially lower embodied carbon factor than what's used here.
Common Use Cases
- Architects and builders comparing structural material options during early design for carbon impact alongside cost.
- Homeowners or renovators curious about the manufacturing footprint behind materials like a new brick facade or steel beam.
- Students or researchers needing a quick reference calculation for embodied carbon coursework or reports.