Free Online Ternary Plot Maker
Plot three-component compositions on a triangular axis. Used in chemistry, geology, and materials science.
Create Your Ternary Plot Now — It's FreeWhat Is a Ternary Plot?
Key components include the triangular frame, gridlines parallel to each side, scatter points or filled regions, axis labels for each component, and optional contour overlays showing concentration zones. Ternary plots are the standard visualization in chemistry, petrology, and materials science for any system where exactly three ingredients determine the outcome.
What Data You Need for a Ternary Plot
Each row needs three non-negative component values that sum to 100% (or 1.0) for a single point, optionally with a label or category. For example: Sample, Sand, Silt, Clay → "S1, 70, 20, 10".
When to Use a Ternary Plot
Ternary plots are essential in geology, chemistry, and materials science. They work best when all three components are meaningful and none is dominant. Choose a ternary plot over a scatter plot when the sum constraint matters. If your data has more than three components, consider parallel coordinates or a radar chart. Normalize values to 100% before plotting.
Where a Ternary Plot Works Best
- Soil texture classification, plotting sand/silt/clay percentages to place samples into USDA texture classes like loam or clay loam.
- Petrology, classifying igneous rocks by their quartz/feldspar/plagioclase (QAP) mineral proportions.
- Metallurgy and chemistry, mapping three-component alloy or solution compositions across a phase diagram.
- Political or market share analysis where three parties or brands split a fixed 100% of votes or spend across regions.
Ternary Plot Example: Soil Texture Samples
A field team measures the sand, silt, and clay fractions of topsoil from four plots, each normalized to 100%. Plotting them on a ternary triangle places each plot in a standard soil texture class.
Sample data: PlotA: 70 sand, 20 silt, 10 clay; PlotB: 30, 50, 20; PlotC: 20, 25, 55; PlotD: 40, 40, 20
PlotA sits in the sandy-loam corner while PlotC falls deep in the clay region, showing the plots span very different drainage and tillage needs despite all summing to 100%.
How to Create a Ternary Plot Online
- Step 1: Open ChartLoad and select the Ternary Plot type from the chart picker on the main page
- Step 2: Enter three columns of values — one per component — ensuring each row sums to 100%
- Step 3: ChartLoad positions each data point on the triangular axis based on its three-component composition
- Step 4: Add multiple datasets or color-code points by category to compare different sample groups
- Step 5: Customize axis labels, gridline density, marker styles, and the chart title for your domain
- Step 6: Click Export and download your ternary plot as PNG, PDF, SVG, JPEG, or WebP
Ternary Plot Best Practices & Tips
- Normalize all three components to sum to 100% before plotting — the ternary coordinate system requires this.
- Add gridlines at 10% or 20% intervals to help readers estimate compositions without counting from the vertices.
- Color-code points by sample group or experiment condition to compare compositions across categories.
- Label the three vertices clearly with the component names — the axes in a ternary plot are not obvious to all audiences.
- Draw classification boundaries (e.g., soil texture regions) on the plot to contextualize where data points fall.
- Overlay classification boundaries on the ternary plot (e.g., USDA soil texture classes) for contextual reference.
- Use different marker shapes for different sample groups to add a categorical dimension beyond color.
- Use contour overlays on the ternary scatter plot to show density regions and concentration zones where the majority of sample compositions cluster within the triangular coordinate space.
Common Ternary Plot Mistakes to Avoid
- Plotting rows whose three components don't sum to 100% (e.g. 50/30/15 = 95%) — the point lands in the wrong place, so always normalize each row to a constant total first.
- Trying to encode a fourth independent variable on the three axes — a ternary triangle only has three degrees of freedom (and really two, since the third is fixed by the other two), so a fourth proportion can't be a vertex.
- Misreading a point's value by following the wrong axis direction — each component is read along grid lines parallel to the side opposite its vertex, not by dropping straight to the nearest edge.
Frequently Asked Questions
Do values need to sum to 100?
Yes, the three components must represent a complete composition summing to 100%.
How do I read a ternary plot?
Each corner represents 100% of one component. Points near a corner are dominated by that component.
Can I use a ternary plot for mixtures that do not sum to 100?
No. Ternary plots require three components that together represent a complete whole. If your components do not naturally sum to a constant, normalize them first or consider a scatter plot or parallel coordinates chart instead.
Related Chart Types
Ready-Made Ternary Plot Templates
Skip the blank canvas — open a free, editable Ternary Plot template, swap in your own data, and export. Browse all templates.
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