Error bars show the range of uncertainty around your data points
Error bars are lines extending above and below (or left and right of) each data point on a chart. They represent the margin of error, standard deviation, or confidence interval for that measurement. In Excel, you add them through the chart itself, not the underlying data — the chart reads your numbers and calculates or displays the bars based on rules you set.
The process differs slightly depending on whether you're using Excel on Windows or Mac, and whether your chart is already built. But the core steps are the same: select the data series on the chart, open the error bar menu, and choose how you want the bars calculated or sized.
Key Takeaways
- Error bars are added to a chart after it exists, not to the data table itself — you right-click the data series (the line or bars) on the chart to access the error bar options.
- Excel can calculate error bars automatically using standard deviation, standard error, or a percentage of the value, or you can specify a fixed amount or use a separate column of error values.
- You can set different error bar sizes for positive and negative directions, and you can add them to only some data series in a multi-series chart.
- Error bars appear on scatter plots, line charts, bar charts, and column charts, but the method to add them is the same across all chart types.
Build your chart first, then add error bars
Error bars live on the chart, not in your spreadsheet. Start by creating your chart normally — select your data, go to the Insert tab, and choose your chart type. Once the chart is on the sheet and you can see it, you're ready to add error bars.
Click on the chart to select it, then click once more on the data series itself (the line, dots, or bars representing your values). You'll see small squares appear at each data point — that's how you know the series is selected. Right-click on one of those points or on the line itself and choose Format Data Series (Windows) or Format Data Point (Mac).
Use standard deviation or standard error for automatic calculation
The easiest route is to let Excel calculate the error bars for you. In the Format Data Series pane that opens, look for the Error Bars section. Click the dropdown next to Error Bar Options and choose Standard Deviation or Standard Error.
Standard Deviation shows how spread out your individual measurements are around the average. If you choose this, Excel multiplies the standard deviation by a number you set (usually 1 or 2) to show the range. Standard Error is smaller — it shows the uncertainty in the average itself, not the spread of individual points. Use Standard Error if you're comparing group averages; use Standard Deviation if you're showing the variability within each measurement.
If you pick either option, a field appears where you can enter a multiplier. Leave it at 1 for one standard deviation or one standard error. Enter 2 to show two standard deviations (which covers roughly 95 percent of your data if it's normally distributed).
Set a fixed error amount or percentage
If you don't want Excel to calculate anything, you can specify a fixed number. In the Error Bar Options dropdown, choose Fixed Value. Enter the amount — for example, if your measurements are in dollars and you want error bars of ±$5, type 5. The bars will be the same size on every point.
Alternatively, choose Percentage to make the error bars a percentage of each value. If you enter 10, a data point at 100 will have bars extending to 90 and 110. A point at 50 will have bars at 45 and 55. This is useful when your data spans a wide range and a fixed amount would be too small for large values or too large for small ones.
Use a separate column for custom error values
If your error amounts vary from point to point — perhaps because different measurements have different levels of uncertainty — you can pull error values from a separate column in your spreadsheet. In the Error Bar Options dropdown, choose Custom.
Excel will ask you to specify the range for positive error values and negative error values. Click the range selector button next to Positive Error Value and drag to select the column containing your positive error amounts. Do the same for Negative Error Value if your errors are asymmetrical (different above and below the point). If your errors are the same in both directions, you can use the same column for both.
Your error column should have one value per data point, in the same order as your data. If you have 12 data points, your error column needs 12 values.
Control the appearance and direction of error bars
Once you've set the size or source of your error bars, you can adjust how they look. In the same Format Data Series pane, look for options to change the line color, line width, and line style (solid, dashed, dotted). You can also set the cap width — the small horizontal line at the top and bottom of each error bar.
By default, error bars extend in both directions (above and below, or left and right). If you want them to go only one direction, look for the Direction option and choose Plus (bars extend upward or rightward only) or Minus (bars extend downward or leftward only).
Add error bars to only some data series
If your chart has multiple data series (multiple lines or groups of bars), you can add error bars to all of them or just one. To add them to a single series, click the chart, then click only that series — the one you want error bars on. Follow the steps above. The error bars will appear only on that series.
To add error bars to a different series, click the chart again, then click the second series, and repeat. You can give each series different error bar styles, sizes, or calculation methods. This is useful when some measurements are more reliable than others, or when you want to highlight uncertainty on one metric but not another.
Frequently Asked Questions
Can I add error bars to a pie chart or doughnut chart?
No. Error bars only work on charts that have a numeric axis — scatter plots, line charts, bar charts, column charts, and area charts. Pie and doughnut charts don't have a numeric axis, so Excel doesn't offer the error bar option for them.
What's the difference between error bars that go both directions and ones that go only up?
Bars that go both directions (plus and minus) show the full range of uncertainty around each point. Bars that go only up or only down are sometimes used to show only the positive error (like "this measurement could be higher") or only the negative error (like "this measurement could be lower"). Choose based on what your data represents.
How do I remove error bars after I've added them?
Click the chart, then click the data series with error bars. Right-click and choose Format Data Series. In the Error Bars section, click the dropdown and select None. The bars will disappear immediately.
Can I make error bars different colors for different data series?
Yes. Select each data series one at a time, open its Format Data Series pane, and set the line color separately for each. This lets you color-code error bars to match their data series or make them stand out differently.
What if my error values are larger than my data values?
Excel will still draw the bars. If an error bar extends below zero on a chart that starts at zero, the bar will go below the axis line. This is mathematically correct and sometimes happens with small measurements or large uncertainties. If it looks wrong, check your error values and your data values to make sure they're in the same units.