Calculator Inputs
Formula Used
The calculator estimates each stage separately. It then adds the stages into total life cycle results.
- Material carbon = material mass × quantity × material emission factor, including scrap.
- Manufacturing carbon = manufacturing energy × energy factor + process carbon.
- Transport carbon = distance × transported weight in tons × freight emission factor.
- Use carbon = annual energy × service years × quantity × use energy factor + maintenance emissions.
- End of life carbon = landfill mass × disposal factor − recycled mass × recycling credit.
- Total carbon = materials + manufacturing + transport + use phase + end of life.
- Carbon per functional unit = total carbon ÷ functional unit count.
Energy, water, waste, and cost use the same stage-based method. Negative end of life values can happen when recycling credits are larger than disposal burdens.
How to Use This Calculator
- Enter a product name and define the functional unit.
- Add the quantity and total functional unit count.
- Enter material mass, emission factors, water, energy, scrap, and costs.
- Fill manufacturing, transport, use phase, and end of life values.
- Press the calculate button.
- Review the result cards, stage table, and Plotly chart.
- Use CSV or PDF export for reports, notes, or scenario records.
Example Data Table
| Input | Example Value | Meaning |
|---|---|---|
| Material mass | 0.45 kg/unit | Weight of main material in one product. |
| Material factor | 2.70 kg CO₂e/kg | Embodied carbon of selected material. |
| Manufacturing energy | 0.90 kWh/unit | Production electricity or fuel per product. |
| Transport distance | 600 km | Average route from factory to market. |
| Use energy | 0.35 kWh/year | Operating energy per unit each year. |
| Recycling rate | 35% | Share of product mass recovered after use. |
Life Cycle Assessment Guide
Overview
A life cycle assessment studies a product from raw input to final disposal. It helps teams see hidden impacts that are often missed during normal costing.
Why This Calculator Matters
Every product carries a footprint. Materials need extraction. Factories use energy. Transport burns fuel. Customers may use power for years. Disposal can create waste or recovery benefits. This calculator joins those parts into one clear estimate. It is useful for design teams, buyers, students, and sustainability reports.
Main Assessment Stages
The tool separates five stages. The material stage covers embodied carbon, water, cost, and scrap. The manufacturing stage covers production energy and process waste. The transport stage uses tonne kilometres. The use stage adds operating energy, maintenance inputs, and service years. The end of life stage estimates landfill burden and recycling credit.
How Results Help
The total impact shows the full product load. The per functional unit result makes products easier to compare. Stage percentages show where improvement should start. A high material share may point to lighter design or recycled content. A high use share may point to efficiency upgrades. A high transport share may point to local sourcing.
Good Data Practices
Use the same boundary for each comparison. Enter values per product unit where requested. Keep emission factors from trusted databases, suppliers, or internal records. Update them when suppliers, energy sources, or routes change. Record assumptions beside each result. This keeps the estimate transparent.
Limits of the Estimate
This calculator is a planning tool. It cannot replace a verified assessment. Real studies may include allocation rules, regional power mixes, uncertainty ranges, and impact categories like toxicity or land use. Still, the calculator gives a strong early view. It supports better choices before designs become expensive to change.
Scenario Review
Use the CSV and PDF exports for review meetings. Compare scenarios often. Small changes across many units can create large savings.
Better Comparisons
For best results, create a baseline first. Then copy the same inputs and change one choice at a time. Test lighter materials, cleaner electricity, shorter routes, longer product life, or better recovery rates. This makes each option easier to explain. Share notes with stakeholders so every decision has documented context.
FAQs
1. What is a life cycle assessment?
A life cycle assessment estimates impacts from materials, manufacturing, transport, use, and disposal. It helps compare design choices and find the biggest improvement areas.
2. What does kg CO₂e mean?
kg CO₂e means kilograms of carbon dioxide equivalent. It combines different greenhouse gases into one comparable climate impact value.
3. Can I compare two products?
Yes. Run the calculator once for each product. Use the same functional unit, boundary, and data quality for a fair comparison.
4. Why can end of life carbon be negative?
End of life carbon can be negative when recycling credits are larger than landfill or disposal emissions. This shows potential recovery benefits.
5. What is a functional unit?
A functional unit defines the service being measured. Examples include one product, one year of use, one wash cycle, or one delivered package.
6. Are the results verified?
No. This is an estimation tool. Verified studies need reviewed data, clear standards, uncertainty checks, and formal documentation.
7. Which stage should I improve first?
Start with the stage showing the largest carbon share. Then check cost, waste, and water to avoid shifting burdens elsewhere.
8. Can I use supplier data?
Yes. Supplier data is often better than generic values. Keep notes about source, date, region, and assumptions for every factor.