How to Add a Trendline to Google Sheets

Evan Gower May 17, 2021

If you’re in finance or any department that works closely with data, you’ll understand the importance of a trendline.

Various software packages that operate with huge amounts of data need trendlines. It’s the best way to spot particular behaviors and patterns during a particular time period.

However, not all data-entry software has this option. But if you use Google Sheets, you’re in luck. This article will explain how to quickly add a trendline to this popular spreadsheet program.

Adding a Trendline

Before you start: You need to have a ready-made chart in your spreadsheet so you can insert a trendline. If you don’t, you won’t be able to access the necessary steps.

How to Add a Chart?

If you never added a chart to your Google sheet before, here are a few simple instructions:

Open your spreadsheet.
Click the “Insert” tab at the top of the screen.
Select “Chart”.

You can customize your chart in the menu that will appear to the left. Among other things, this is the place where you can add a trendline.

How to Add a Trendline?

You can insert a trendline to a column, line, bar, and scattered charts on your spreadsheet. The entire process is fairly simple. Just follow these steps:

Launch Google Sheets.
Open the desired spreadsheet.
Double-click the chart.
Select the “Customize” tab on the menu to the right.
Click the “Series” menu to display new options.
Tick the “Trendline” option.

If you want, you can choose the data sequence to apply the trendline to. Just select it next to the “Apply to” option in the menu.

Now that you know how to add a trendline, you can also customize it according to your preferences.

Customizing a Trendline

Google Sheets allows you to make changes to the added trendline. If you want to display some additional, more complex operations you need to do this:

Double-click the chart on your spreadsheet.
Select “Customize” on the top-right of the screen.
Click “Series”.
Under the “Trendline,” you’ll see a bunch of new options that you can tweak.
Trendline Types: Linear, Exponential, Polynomial, Logarithmic, Power Series, Moving Average
Line color
Line opacity
Line thickness
Label: You can add a custom label, use equation, or have no label at all
Show R²: To see whether your trendline is precise. If your R² is close (or equals) 1, the more accurate it is. However, you need to add a legend for this option.
Polynomial degree: If you choose the polynomial trendlines, you can add polynomial degrees.
Average type: Available if you’re moving average trendlines
Periods: Same as above

Which Equations Should You Use?

When you add a trendline you should know which equations fits it. Here are some examples:

Linear: If you have a data that follows a straight line you use this trendline. y=mx+b
Exponential: If your data will increase and decrease according to its current value. y = A*e^(Bx)
Logarithmic: If you have a quickly increasing or reducing data that later flattens out. y = A*ln(x) + B.
Polynomial: For changing data (varying data). ax^n + bx^(n-1) +…+ zx^0.
Power series: If you have data that increases and decreases (rises or falls) according to its present value at the same rate. y = A*x^b.
Moving average: You can use it to smoothen out varied or unstable data.

Trendlines Everywhere

As you see, adding trendlines is simple. However, understanding the complex processes and equations behind them is a tough cookie. If you know what you want, you can add trendlines in minutes.

On the other hand, make sure that you have a well-prepared chart on your spreadsheet. If you’re missing a chart, you’ll obviously miss out on a trendlines as well.

Furthermore, it’s essential to know what type of trendline you need. If you don’t choose the wrong equation or input wrong data, your entire trendline may show false results.

What kind of trendline do you need? Did you have trouble setting it up? Leave a comment below and let us know.