Calculator
Example data table
| Material | Cost | Recycled % | Type | Factor | Contribution |
|---|---|---|---|---|---|
| Recycled steel rebar | USD 12,000.00 | 85% | Post-consumer | 1.00 | USD 10,200.00 |
| Concrete with SCMs | USD 9,500.00 | 25% | Pre-consumer | 0.50 | USD 1,187.50 |
| Reclaimed wood framing | USD 4,200.00 | 100% | Post-consumer | 1.00 | USD 4,200.00 |
| Total | USD 25,700.00 | — | — | — | USD 15,587.50 |
| Overall recycled content | 60.65% | ||||
Formula used
How to use this calculator
- Choose a basis: use cost for purchasing, or weight for materials.
- Set currency or weight unit to match your documentation.
- Add each material as a line item with its amount.
- Enter the recycled percentage for that product line.
- Select post-consumer or pre-consumer recycled source.
- Optionally apply the legacy pre-consumer weighting factor.
- Set a target percentage if your spec requires one.
- Press calculate to show results above the form.
- Download CSV or PDF to support submittals and audits.
Why recycled content matters
Recycled content reduces demand for virgin extraction, supports supply chains, and can contribute to sustainability credits. Many owners specify recycled percentages for steel, concrete constituents, roofing, and finishes. A consistent calculation method improves comparability between bids, alternates, and change orders when multiple trades provide different documentation. It shows where recycled inputs are concentrated, helping teams protect those selections during value engineering.
Choosing a calculation basis
This calculator supports cost or weight basis. Cost basis fits procurement because quotes, invoices, and schedules of values are priced and auditable. Weight basis fits mix designs and bulk commodities where price shifts, such as aggregates, asphalt, or rebar by ton. Select one basis and keep units consistent across all items. If you change basis, rerun the dataset so reporting stays clear.
Handling pre and post consumer inputs
Post-consumer material is recovered after end use, such as reclaimed timber, recycled steel from demolition, or recycled glass. Pre-consumer material comes from manufacturing scrap, offcuts, and process waste diverted back into production. Some specifications discount pre-consumer content, so the tool can apply a legacy factor to weight its contribution. Enter recycled percentages exactly as stated by the manufacturer, and avoid estimates without written support.
Documentation and verification
Accurate results depend on traceable evidence. Gather mill certificates, environmental product declarations, and supplier letters that state recycled content and identify whether it is post or pre consumer. Match documents to purchase orders and delivery tickets. For bundled assemblies, allocate percentages carefully to avoid double counting. Keep a revision log when substitutions occur, and store supporting files with your exported report.
Using results for specifications
Use the overall percentage to test compliance against project targets, client standards, or tender requirements. Review the line item table to spot low performing products and substitute higher recycled alternatives with equivalent performance. Export CSV for spreadsheets and PDF for submittals. Update inputs as quantities or pricing change to maintain an accurate running total and defend sustainability commitments.
FAQs
What should I use as the amount for each line item?
Use the same basis for every item. For cost basis, enter the approved value from quotes, invoices, or schedules. For weight basis, enter measured or specified quantities in a single unit across the table.
How do I find the recycled percentage for a product?
Use manufacturer documentation such as product data sheets, EPDs, or letters stating recycled content. If a range is given, use the conservative value required by your specification and keep the source on file.
When should I classify content as pre-consumer versus post-consumer?
Post-consumer comes from material recovered after end use. Pre-consumer comes from manufacturing scrap and process waste. If documentation is unclear, request a clarified statement to avoid misclassification.
Why does the calculator include a legacy weighting factor?
Some project requirements count pre-consumer recycled content at a reduced value. The weighting option applies that reduction consistently across all pre-consumer entries so totals align with stricter specifications.
How can I improve the overall recycled content percentage?
Review the line item table and focus on high-cost or high-weight items first. Substituting those with equivalent products that have higher verified recycled percentages usually changes the total fastest.
How do the CSV and PDF exports help during reviews?
Exports create a snapshot with inputs, factors, and totals that reviewers can trace. Attach the PDF to submittals and use the CSV for internal checks, scenario testing, and reconciliation with procurement logs.