Business Carbon Footprint Calculator
Estimate your company's total carbon footprint across Scope 1, 2, and 3 emissions. Enter direct, energy, and supply chain data to see total CO2 in tonnes per year.
Steel Carbon Calculator
Calculate CO2 emissions from steel production. Enter tonnes of steel and select production method to estimate embodied carbon from structural and reinforcing steel.
tonnes
%
%
$/tonne CO₂
Total CO₂ Emissions⧉
181.30 t
105.00 t steel incl. 5% waste
Carbon Intensity⧉
1.813 t CO₂/t
Total emissions per tonne ordered
Production CO₂⧉
179.70 t
99.1% of total emissions
Transport CO₂⧉
1.58 t
0.9% of total emissions
Carbon Cost⧉
$9,063.00
At $50/tonne CO₂
Savings vs BOF⧉
14.60 t CO₂
7.4% reduction
Production Route Comparison
BOF (Blast Furnace)
195.80 t
EAF (Scrap)
54.10 t
Green Steel (H2-DRI)
12.10 t
Your Selection
181.30 t
Steel Production Methods Reference
| Method | Factor (t CO₂/t) | Recycled Input | Energy Source | Note |
|---|---|---|---|---|
| BOF (Blast Furnace) | 1.85 | 0–25% | Coal/Coke | 70% of global production |
| EAF (Grid Average) | 0.50 | 85–100% | Electricity | 30% of global production |
| EAF (Renewable) | 0.35 | 85–100% | Renewable elec. | Leading EAF mills |
| H2-DRI (Green Steel) | 0.10 | 0–30% | Green hydrogen | Emerging (SSAB, H2GS) |
| Theoretical Zero | 0.00 | 100% | Renewable + CCS | Not yet at scale |
Equivalent Impact
| Equivalent | Value |
|---|---|
| Passenger car years (4.6 t CO₂/yr) | 39.40 car-years |
| Flights NYC→London (0.9 t CO₂) | 201.00 flights |
| Homes powered for a year (7.5 t CO₂) | 24.20 homes |
| Trees needed to offset (21 kg/yr) | 8,633.00 trees |
Planning notes, formulas, and examples
About the Steel Carbon Calculator
Steel production is responsible for approximately 7–8% of global CO2 emissions. The carbon intensity depends heavily on the production route: blast furnace with basic oxygen furnace (BOF) using iron ore produces about 1.85 tonnes of CO2 per tonne of steel, while electric arc furnace (EAF) using recycled scrap produces about 0.4–0.6 tonnes per tonne.
This Steel Carbon Calculator estimates CO2 emissions from your steel requirements. Enter the quantity in tonnes and select the production method. The calculator shows total embodied CO2 and compares different production routes so you can make informed procurement decisions.
As green steel initiatives (hydrogen-based direct reduction, renewable-powered EAF) gain traction, understanding your steel's carbon footprint is increasingly important for sustainable construction and manufacturing.
Tracking this metric consistently enables energy professionals and facility managers to identify consumption trends and implement efficiency improvements before costs escalate unnecessarily. This measurement provides a critical foundation for energy auditing and sustainability reporting, helping organizations meet regulatory requirements and voluntary environmental commitments.
When This Page Helps
Steel procurement decisions significantly impact a project's embodied carbon. This calculator helps specify lower-carbon steel production routes, quantify the difference, and support green procurement policies.
How to Use the Inputs
- Enter the total steel quantity in tonnes.
- Select the production method (BOF, EAF, or custom).
- View total CO2 and the comparison with alternative methods.
- Use results to inform procurement specifications.
Formula used
CO2 (tonnes) = Steel (tonnes) × Emission Factor. BOF: ~1.85 t CO2/t steel. EAF (scrap): ~0.5 t CO2/t steel. Green steel (H2-DRI): ~0.1 t CO2/t steel.Example Calculation
Result: 185 tonnes CO2
Steel: 100 tonnes. BOF factor: 1.85 t CO2/t. Total: 100 × 1.85 = 185 tonnes CO2. Using EAF instead: 100 × 0.5 = 50 t, saving 135 tonnes.
Tips & Best Practices
- Specify minimum recycled content in procurement to drive EAF demand.
- EAF steel from recycled scrap has 70–75% lower emissions than BOF.
- Request mill-specific EPDs rather than using industry averages.
- Emerging green steel (H2-DRI) can cut emissions by 95% but supply is limited.
- Optimize structural design to reduce steel tonnage without compromising safety.
- Consider steel alternatives (mass timber, FRP) for some applications.
BOF vs EAF Production Routes
The steel industry is bifurcated: BOF plants use iron ore and coal, producing about 70% of global steel with high emissions. EAF plants use scrap and electricity, producing 30% with much lower emissions. Increasing EAF share is a key industry decarbonization strategy.
The Hydrogen Revolution
Hydrogen-based steelmaking replaces coal-fired blast furnaces with direct reduction using green hydrogen. Projects in Sweden (HYBRIT/SSAB), Germany, and elsewhere aim to commercialize green steel by 2030. This could eventually eliminate most steel emissions.
Procurement as a Lever
Specifying low-carbon steel sends a demand signal to producers. "Buy Clean" policies in California and the EU are setting maximum embodied carbon limits for publicly funded projects. Even without mandates, specifying green steel accelerates the transition.
Sources & Methodology
Last updated:
Frequently Asked Questions
Basic Oxygen Furnace steel uses iron ore reduced in a blast furnace with coke (coal). This traditional route is the most carbon-intensive, producing about 1.85 tonnes of CO2 per tonne of crude steel. It accounts for about 70% of global production.
Electric Arc Furnace steel primarily uses recycled scrap metal melted by electricity. Its carbon footprint depends on the grid: with renewable electricity, it can be very low. Global average is about 0.5 t CO2/t steel.
Green steel replaces coal with hydrogen for iron ore reduction (Hydrogen Direct Reduced Iron, or H2-DRI). If the hydrogen is produced from renewable electricity, emissions can drop to near zero. Companies like SSAB and H2 Green Steel are pioneering this approach.
Steel has one of the highest recycling rates of any material — about 85–90% of structural steel is recycled at end of life. However, scrap supply constraints mean that BOF production is still necessary to meet global demand.
Include maximum embodied carbon requirements in your procurement specs (e.g., ≤1.0 t CO2/t for structural sections). Request EPDs, specify minimum recycled content, and consider sourcing from mills with published decarbonization plans.
Rebar (reinforcing steel) is typically produced via EAF from scrap, so its emission factor is lower (~0.5 t CO2/t). Structural sections from BOF have higher factors. This calculator lets you select the appropriate method for your steel type.
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