How to Add Trendline in Excel - Practical Guide

Learn how to add trendlines to Excel charts to visualize data patterns and forecast trends. Trendlines help identify relationships in your data, making it easier to spot upward/downward movements and make data-driven decisions. This essential charting skill enhances data analysis and presentation clarity.

Why This Matters

Trendlines reveal hidden patterns in datasets, enabling better forecasting and strategic decision-making. They're essential for presenting professional data analysis in business reports and dashboards.

Prerequisites

•An Excel chart already created (scatter, line, column, or bar chart)
•Data plotted on a chart with at least two data points
•Access to Chart Design or Layout tabs in Excel

Step-by-Step Instructions

Select your chart

Click on the chart to select it. You'll see the chart border highlight and Chart Design tab appear in the ribbon.

Right-click on the data series

Right-click directly on one of the data points or lines in your chart to open the context menu.

Choose Add Trendline option

From the context menu, select 'Add Trendline' (or 'Ajouter une courbe de tendance' in French Excel).

Select trendline type

In the Format Trendline pane, choose from Linear, Exponential, Power, Logarithmic, Polynomial, or Moving Average based on your data pattern.

Customize and apply

Optionally check 'Display Equation on chart' or 'Display R-squared value' for analysis, then close the pane to apply the trendline.

Alternative Methods

Using the Chart Design ribbon tab

Select the chart, go to Chart Design > Add Chart Element > Trendline, then choose your trendline type from the submenu.

Ribbon menu (Analysis Tools)

With chart selected, use Chart Design tab > Add Chart Element dropdown to access trendline options directly.

Tips & Tricks

✓Use Linear trendlines for data showing consistent growth or decline; Polynomial for curved patterns.
✓Display the R² value to assess how well the trendline fits your data (closer to 1.0 is better).
✓Format trendline color and style by right-clicking the trendline and selecting 'Format Trendline'.
✓Moving Average trendlines work best for volatile data with many fluctuations.

Pro Tips

★Combine multiple trendlines on the same chart for different data series to compare trends across datasets.
★Use Polynomial (Order 2-3) trendlines when linear doesn't capture your data pattern accurately.
★Enable 'Forecast' option in Format Trendline pane to project future values beyond your current data range.
★Export charts with trendlines to PowerPoint for professional presentations.

Troubleshooting

Trendline option is grayed out or missing

Ensure your chart type supports trendlines (Scatter, Line, Column, Bar, Area). Bubble and Stock charts have limited trendline support. Also verify you've selected the chart first.

Trendline doesn't match my data pattern

Try different trendline types: Linear, Polynomial (increase order), Exponential, or Logarithmic. Check the R² value—values below 0.7 indicate poor fit.

Can't see the trendline equation clearly

Move the equation box by clicking and dragging it, or reduce font size via Format Trendline pane. Alternatively, uncheck equation display and rely on the R² value.

Adding multiple trendlines is confusing

Add one trendline per data series separately. Right-click each series individually and add its trendline. Use different colors to distinguish them.

Related Excel Formulas

FORECAST TREND LINEST LOGEST SLOPE INTERCEPT

Frequently Asked Questions

What is an R² value and why does it matter?

The R² value (coefficient of determination) measures how well the trendline fits your data, ranging from 0 to 1. A value of 0.9 or higher indicates an excellent fit, while 0.7-0.9 is good. Lower values mean the trendline doesn't accurately represent your data trend.

Can I add a trendline to a pie chart or donut chart?

No, trendlines are only supported on Scatter, Line, Column, Bar, Bubble, Stock, and Area charts. Pie and donut charts don't support trendlines because they don't show trends over time or continuous data ranges.

How do I forecast future values using a trendline?

In the Format Trendline pane, scroll to the Forecast section and set the 'Forward' value (e.g., enter 5 to forecast 5 periods ahead). The trendline will extend beyond your data to show predicted future values.

Which trendline type should I choose for my data?

Use Linear for steady growth/decline, Exponential for rapid acceleration, Polynomial for curved patterns, Logarithmic for quickly leveling trends, and Moving Average for smoothing volatile data. Start with Linear and check the R² value; switch types if the fit is poor.

Can I format the trendline color and line style?

Yes, right-click the trendline and select 'Format Trendline'. In the Format pane, go to Line Color and Line Style tabs to customize appearance, thickness, and dash pattern.