Please Note: This article is written for users of the following Microsoft Excel versions: 2007, 2010, 2013, 2016, 2019, and Excel in Office 365. If you are using an earlier version (Excel 2003 or earlier), this tip may not work for you. For a version of this tip written specifically for earlier versions of Excel, click here: Reading Values from Graphs.

Reading Values from Graphs

by Allen Wyatt
(last updated February 17, 2020)

4

When creating charts from Excel data, you can smooth out the lines between data points by using any number of methods. At some point, you may want to actually figure out how Excel does its calculations to determine where to actually plot points along the line. Rather than visually trying to figure out where a point falls,

If you are using Excel 2013 or a later version, follow these steps:

  1. Right-click on the data series in question. Excel displays a Context menu.
  2. Choose the Add Trendline option from the Context menu. Excel displays the Format Trendline pane at the right side of the screen. (See Figure 1.)
  3. Figure 1. The Format Trendline task pane.

  4. Make sure the regression type you want to use is selected.
  5. Make sure the Display Equation on Chart check box is selected.
  6. Close the task pane.

If you are using Excel 2007 or Excel 2010, the steps are different only in that Excel uses a dialog box instead of a task pane:

  1. Right-click on the data series in question. Excel displays a Context menu.
  2. Choose the Add Trendline option from the Context menu. Excel displays the Format Trendline dialog box. (See Figure 2.)
  3. Figure 2. The Format Trendline dialog box.

  4. Make sure the regression type you want to use is selected.
  5. Make sure the Display Equation on Chart check box is selected.
  6. Click on OK.

The result is that Excel shows a formula, on the chart, that represents how it calculated each point along the line. You can then use this formula to determine points, as well. No more guessing! Once you know the formula, you can turn off the formula display if you want it off.

If you would like to know the different formulas that Excel uses for different types of trend lines, you can use the online Help system to search for "equations for calculating trendlines."

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (10698) applies to Microsoft Excel 2007, 2010, 2013, 2016, 2019, and Excel in Office 365. You can find a version of this tip for the older menu interface of Excel here: Reading Values from Graphs.

Author Bio

Allen Wyatt

With more than 50 non-fiction books and numerous magazine articles to his credit, Allen Wyatt is an internationally recognized author. He is president of Sharon Parq Associates, a computer and publishing services company. ...

MORE FROM ALLEN

How Many Rows and Columns Have I Selected?

Want a quick way to tell how may rows and columns you've selected? Here's what I do when I need to know that information.

Discover More

Setting Decimal Tabs in a Table Using the Keyboard

Most people use the mouse to set tab stops in the paragraphs in a table. If you prefer to not use the mouse, then you'll ...

Discover More

Organizing the All Programs Menu

All of the programs installed on your system are visible when you choose All Programs from the Start menu. If you want to ...

Discover More

Comprehensive VBA Guide Visual Basic for Applications (VBA) is the language used for writing macros in all Office programs. This complete guide shows both professionals and novices how to master VBA in order to customize the entire Office suite for their needs. Check out Mastering VBA for Office 2010 today!

More ExcelTips (ribbon)

Using Dynamic Chart Titles

Want the title of your chart to change based upon what is placed in a worksheet cell? It's easy; just add a formula to ...

Discover More

Hyperlinks to Charts

You can create hyperlinks to all sorts of worksheets in a workbook, but you cannot create a hyperlink to a chart sheet. ...

Discover More

Changing Chart Types

Want to change an existing bar chart to a different type of chart, such as a line chart or a column chart? It's easy to ...

Discover More
Subscribe

FREE SERVICE: Get tips like this every week in ExcelTips, a free productivity newsletter. Enter your address and click "Subscribe."

View most recent newsletter.

Comments

If you would like to add an image to your comment (not an avatar, but an image to help in making the point of your comment), include the characters [{fig}] in your comment text. You’ll be prompted to upload your image when you submit the comment. Maximum image size is 6Mpixels. Images larger than 600px wide or 1000px tall will be reduced. Up to three images may be included in a comment. All images are subject to review. Commenting privileges may be curtailed if inappropriate images are posted.

What is 2 + 9?

2016-09-12 09:21:29

Rogério Fernandes

Hi,

I need to display in a chart, the values or at least the final value of a trend line. Maybe using a second line (blank). Can you help me with this?

thanks
RF


2015-07-27 05:54:39

DaveS

Yes, that seems to work OK. The LINEST function needs to be applied as an array formula. For a 4-term polynomial y=ax^3+bx^2+cx+d, define dynamic named ranges for Y data column (say, YRange)and X data column (say, XRange), then enter the formula

=LINEST(YRange,XRange^{1,2,3}) in a spare cell (say, H9)

Drag formula horizontally across three more cells (say, to K9)

While these cells are highlighted, press F2 function key, and then while still highlighted press Ctrl-Shift-Enter

This then returns the coefficients (H9=a, I9=b, J9=c, K9=d), which you can use in another formula to recalculate Y for a given X as you add more X,Y data.


2015-07-27 05:16:01

DaveS

For a polynomial regression line the LINEST function can be used to determine the coefficients independently of the chart. I've not tried it, but in principle you could define dynamic named ranges for the X and Y columns (to allow for adding more data), and use these in the LINEST function to automatically recalculate the coefficients as more data is added.


2015-07-25 12:47:02

Erik Oberg

If you want to use Excel's curve fit formula in your own calculations, I recommend showing more significant digits - maybe 10 or more - for best results. If you just use the formula as Excel displays it by default, it will likely yield inaccurate results. As a check, add your calculated points to the graph. If they don't fall exactly on the fit curve, it is a result of the rounded formula values; increase the number of significant digits displayed and try again.


This Site

Got a version of Excel that uses the ribbon interface (Excel 2007 or later)? This site is for you! If you use an earlier version of Excel, visit our ExcelTips site focusing on the menu interface.

Newest Tips
Subscribe

FREE SERVICE: Get tips like this every week in ExcelTips, a free productivity newsletter. Enter your address and click "Subscribe."

(Your e-mail address is not shared with anyone, ever.)

View the most recent newsletter.