Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Total estimated supply chain emissions
2,490.0
From raw materials
1,950.0
From logistics
360.0
Overall intensity (kg CO2e per $)
0.470
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter raw materials/metals spend ($).
- 2Enter materials emission factor (kg CO2e/$).
- 3Enter logistics/transport spend ($).
- 4Enter logistics emission factor (kg CO2e/$).
- 5Enter professional services spend ($).
- 6Enter services emission factor (kg CO2e/$).
- 7Read your total estimated supply chain emissions on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
For most companies, purchased goods and services (GHG Protocol Scope 3 Category 1) is the single largest emissions category, often exceeding Scope 1, 2, and all other Scope 3 categories combined. Since supplier-specific emissions data is rarely available, most companies start with the spend-based method: multiply category spend by an industry-average emissions factor per dollar (EPA's Supply Chain Greenhouse Gas Emission Factors, or similar databases), which gives a directionally useful estimate even without primary supplier data. This calculator applies that method across your top spend categories and shows which categories drive the most emissions per dollar, which is typically where companies focus supplier engagement or category-switching efforts first — a dollar spent on raw metals or chemicals commonly carries far higher embedded emissions than the same dollar spent on professional services.
Worked example
Using the values the calculator loads with:
Inputs
- Raw materials/metals spend: 3000000 $
- Materials emission factor: 0.65 kg CO2e/$
- Logistics/transport spend: 800000 $
- Logistics emission factor: 0.45 kg CO2e/$
- Professional services spend: 1500000 $
- Services emission factor: 0.12 kg CO2e/$
Results
- Total estimated supply chain emissions: 2,490
- From raw materials: 1,950
- From logistics: 360
- Overall intensity (kg CO2e per $): 0.47
What each field means
Inputs
- Raw materials/metals spend ($)
- The raw materials/metals spend used in the calculation, measured in $. Starts at 3000000 $ so you have a working example on load.
- Materials emission factor (kg CO2e/$)
- The materials emission factor used in the calculation, measured in kg CO2e/$. Starts at 0.65 kg CO2e/$ so you have a working example on load.
- Logistics/transport spend ($)
- The logistics/transport spend used in the calculation, measured in $. Starts at 800000 $ so you have a working example on load.
- Logistics emission factor (kg CO2e/$)
- The logistics emission factor used in the calculation, measured in kg CO2e/$. Starts at 0.45 kg CO2e/$ so you have a working example on load.
- Professional services spend ($)
- The professional services spend used in the calculation, measured in $. Starts at 1500000 $ so you have a working example on load.
- Services emission factor (kg CO2e/$)
- The services emission factor used in the calculation, measured in kg CO2e/$. Starts at 0.12 kg CO2e/$ so you have a working example on load.
Results
- Total estimated supply chain emissions
- Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- From raw materials
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- From logistics
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Overall intensity (kg CO2e per $)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How accurate is the spend-based method?
It's directionally useful but coarse — it assumes every dollar in a category has the same emissions intensity regardless of the specific supplier's efficiency or energy mix, which is rarely true. It's the recommended starting method under GHG Protocol when supplier-specific data isn't available, and most companies transition individual high-spend categories to supplier-specific (activity-based) data over time as they mature their program.
Why is materials spend usually the biggest emissions driver?
Raw material extraction and primary processing (steel, aluminum, chemicals, cement) are extremely energy- and process-emissions-intensive per dollar of value added, compared to services or finished-goods assembly where labor and margin make up more of the price. This is consistently the pattern EPA's and DEFRA's spend-based emission factor databases show across sectors.
What should I do once I've identified my highest-intensity spend category?
Engage your largest suppliers in that category for primary emissions data (which usually lowers the estimate versus the generic spend-based factor, since real suppliers vary widely) and consider supplier scorecards or contract language requiring emissions disclosure and reduction targets as a starting point for category-level engagement.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Carbon Intensity per Revenue Calculator
Emissions per dollar of revenue, the metric investors actually benchmark.
Embodied Carbon of Materials Calculator
Upfront carbon footprint of concrete, steel, and other construction materials.
Business Travel Emissions Calculator
Flight and hotel emissions from your company's travel program.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Supply Chain Emissions Intensity Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/supply-chain-emissions-intensity
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/supply-chain-emissions-intensity" target="_blank" rel="noopener">Supply Chain Emissions Intensity Calculator — RevenueLab</a> (2026).</p>
Source: [Supply Chain Emissions Intensity Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/supply-chain-emissions-intensity) (2026).