Free Sankey Diagram Generator
Create precise Sankey diagrams for energy systems, material flow analysis, and process efficiency — upload your flow table and get a labeled, export-ready chart instantly.
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Free Sankey Diagram Generator— templates & examples
Everything you need to build your Sankey diagram
Generate a Sankey diagram from a flow table
Upload a table of sources, targets and weights to SciFig DataChart, then describe your system to generate the proportional flow chart. Band widths scale automatically to your values, nodes are labeled, and the layout is optimized so the Sankey diagram is readable at a glance.
Built for material flow analysis and energy audits
SciFig's online Sankey MFA maker handles the structured flow data that material flow analysis and energy balance studies require. Assign units (tonnes, GJ, kg, kWh), color-code streams by material category or energy type, and export a Sankey diagram that meets publication standards for industrial ecology, environmental engineering, and energy research journals.
Edit flows, nodes, and colors after generation
Every Sankey diagram from SciFig is fully editable. Adjust individual flow widths, rename node labels, split or merge streams, and recolor bands to distinguish input types, losses, and recycled flows. When the Sankey chart matches your data, export it ready for your paper, thesis, or engineering report.
What is a Sankey diagram?
A Sankey diagram is a flow diagram in which band widths are proportional to the quantities they represent, making losses, conversions, and distributions immediately visible across energy systems and material streams. Sankey diagrams are the standard for material flow analysis, energy audits, and industrial ecology. With SciFig DataChart (data-driven charts) in SciFig, upload a table of sources, targets and weights to create a labeled, proportional chart for papers or reports.
Why Sankey diagrams are the standard for flow visualization
- Proportional band widths make losses and efficiencies immediately visible without a legend
- Standard figure format required in material flow analysis and energy audit publications
- Handles multi-input, multi-output systems that line charts and bar charts cannot represent
- Communicates complex process chains to non-specialist readers and decision-makers
- Supports traceability — every unit of material or energy is accounted for across the diagram
- Accepted by leading engineering and environmental science journals as a primary figure type
Key components of a Sankey diagram
- Source nodes — entry points where energy or material enters the system
- Process nodes — intermediate steps where conversion, transformation, or redistribution occurs
- Sink nodes — exit points representing useful output, waste, emissions, or storage
- Flow bands — arrows or ribbons whose width is proportional to flow magnitude
- Flow labels — numerical annotations showing quantities and units on each band
- Loss flows — typically downward-pointing bands indicating waste heat, emissions, or rejected material
Where Sankey diagrams are used in science and engineering
- Energy system analysis: national energy balance, building energy audits, power plant efficiency
- Material flow analysis: metal cycles, plastic waste streams, urban metabolism studies
- Industrial ecology: life cycle inventory visualization, supply chain material tracking
- Chemical engineering: process mass balance and heat integration diagrams
- Environmental engineering: greenhouse gas emission attribution across sectors
- Mechanical and aerospace engineering: thermodynamic cycle and propulsion efficiency diagrams
How to make a Sankey diagram
Upload your table
Upload a CSV or Excel file with the measurements and column names needed for your chart.
Set up the chart and analysis
Choose a chart type, then set the column mapping, units, filters and statistical options; SciFig DataChart plots every value from your table.
Download your results
Export the chart and analysis files, or convert the result to SVG for editing in SciFig Vector Canvas.
Free Sankey Diagram Generator — Frequently Asked Questions
Common questions about Free Sankey Diagram Generator.
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