How to Trend Data in Excel

Trying to figure out if your sales are trending up or just having a good month is impossible if you're only looking at a raw list of numbers. To make smart decisions, you need to spot the underlying patterns hidden in your data. This article will show you exactly how to analyze trends in Microsoft Excel, covering everything from simple visual charts to more advanced forecasting functions.

First Things First: Prepare Your Data for Analysis

Before you can spot any trends, your data needs to be clean, organized, and ready for analysis. Skipping this step is like trying to build a house on an unstable foundation - it's just not going to work. A little prep work upfront saves a lot of headaches later.

Organize Chronologically

Trend analysis is all about tracking changes over time. The most important rule is to make sure your data is in chronological order. Your first column should almost always be a date or time period (e.g., Day, Week, Month, Quarter) sorted from oldest to newest.

• Column A: Date (e.g., 1/1/2024, 2/1/2024, 3/1/2024)
• Column B: The metric you want to analyze (e.g., Sales, Website Visitors, New Leads)

Ensure Consistent Data Formatting

Excel is powerful, but it's not a mind reader. Inconsistencies can break your formulas and charts.

• Dates: Make sure all your dates are formatted as actual dates, not as text. A quick way to check is to try sorting the column. If text-formatted dates don't sort correctly, you'll need to fix them. You can use Excel’s Format Painter or the DATEVALUE function to correct this.
• Numbers: The metrics you’re analyzing should be formatted as numbers. Remove any currency symbols or commas if they're causing issues, or use the "Number" format in the Home tab to standardize the column.

Clean Up Errors and Gaps

Missing data points or obvious typos can skew your trends. Give your spreadsheet a quick review to fix:

• Blank Cells: Decide how you want to handle gaps. For a simple trend line, you might be able to leave them blank. For formulas, you might need to enter a 0 or use an average of the surrounding values, depending on what makes the most sense for your data.
• Duplicates: Use Excel's "Remove Duplicates" tool (found in the Data tab) to get rid of any accidental double entries that could inflate your numbers.

The Easiest Method: Visualizing Trends with Charts

The fastest way to spot a trend is to see it. Our brains are hardwired to process visual information, and an Excel chart can make a pattern jump right off the page in seconds.

Using a Line Chart to See Trends Over Time

A line chart is the go-to choice for trend analysis. It connects individual data points, making it incredibly easy to see the highs, lows, and overall direction of your data over a specific period.

Let’s say you have monthly user sign-ups for the last year:

Step-by-Step Instructions:

1. Select your data range, including the headers (e.g., "Month" and "Sign-ups").
2. Go to the Insert tab on the Ribbon.
3. In the Charts section, click on the "Insert Line or Area Chart" icon.
4. Choose the first option under 2-D Line. Voila! Excel will instantly generate a line chart.

You can immediately see the upward trend in the later months. You can also customize the chart's title, colors, and labels to make it easier to read.

Using a Column Chart for Period-over-Period Comparison

While line charts are great for continuous trends, column or bar charts excel at comparing distinct time periods, like monthly sales this year versus last year.

Step-by-Step Instructions:

1. Organize your data with periods as headers (e.g., Jan, Feb, Mar) and series in rows (e.g., 2023 Sales, 2024 Sales).
2. Select the entire data table.
3. Go to the Insert tab and click the "Insert Column or Bar Chart" icon.
4. Select a 2-D Clustered Column chart.

This chart makes it simple to see which months outperformed the previous year, which is a key part of spotting meaningful trends.

Going Deeper: Adding a Trendline to Your Chart

A simple line chart shows you the noise - the bumps and dips along the way. A trendline cuts through that noise to show you the true, underlying trajectory of your data.

How to Add a Trendline

It only takes a few clicks to add a trendline to any line or scatter plot chart:

1. Create your line chart using the steps above.
2. Click on the chart to select it. A "+" icon (Chart Elements) will appear in the top-right corner.
3. Click the "+" and check the box next to Trendline. A dotted line will appear over your data.
4. To customize it, click the small arrow next to "Trendline" and select "More Options." This opens a format pane where you can fine-tune its appearance and type.

Choosing the Right Type of Trendline

Excel offers several trendline types, but for most business scenarios, these three will cover your needs:

• Linear: This is the default and most common type. It draws a straight line of a trend. Use it when your data is growing or declining at a relatively steady rate, like consistent increases in subscription revenue.
• Moving Average: This type is perfect for smoothing out highly erratic or "noisy" data. Instead of showing the overall trend, it calculates the average of a specific number of preceding data points to reveal a short-term trend. For example, setting the 'Period' to 3 will plot each point as the average of itself and the two previous points. This is great for data like daily website traffic, which can have big, random spikes.
• Exponential: Use this for data that is increasing or decreasing at an ever-accelerating rate. It plots the trend as a curved line. It's often used to model viral growth in content views or user adoption for a new product.

Next Level: Using Excel Formulas for Trend Forecasting

Charts are fantastic for visuals, but sometimes you need hard numbers. Excel formulas can calculate your growth rate and help you forecast future performance with powerful precision.

Finding the Growth Rate with the SLOPE Function

The SLOPE function calculates the steepness of the trendline - in business terms, this is your rate of change for each period. A positive slope means growth, a negative one means decline.

The syntax is:

=SLOPE(known_y's, known_x's)

• known_y's: Your metric values (e.g., the range of cells containing your sales numbers).
• known_x's: Your time period values (e.g., the range of cells for your months, often represented as 1, 2, 3...).

For example, if your sales data is in cells B2:B13 and the corresponding months (numbered 1 through 12) are in A2:A13, the formula would be:

=SLOPE(B2:B13, A2:A13)

If the result is 500, it means that on average, your sales are increasing by $500 each month.

Predicting the Future with the FORECAST.LINEAR Function

Once you know the trend, you can use it to project future results. The FORECAST.LINEAR function does exactly this, calculating a future value along the linear trendline.

The syntax is:

=FORECAST.LINEAR(x, known_y's, known_x's)

• x: The future time period you want to predict (e.g., period 13 for the next month).
• known_y's: Your existing metric values (your sales).
• known_x's: Your existing time periods.

To predict sales for the 13th month, using the same data as before, your formula would be:

=FORECAST.LINEAR(13, B2:B13, A2:A13)

This will give you a specific, number-based prediction to help with planning and goal setting.

An Advanced Approach: Regression Analysis with the Analysis ToolPak

For a much deeper statistical dive, you can use Excel's hidden gem: the Analysis ToolPak. This add-in runs a full regression analysis, giving you detailed information about your trend's reliability.

How to Enable the Analysis ToolPak

First, you need to turn it on, as it's not enabled by default.

1. Go to File > Options.
2. Click on Add-ins in the left-hand menu.
3. At the bottom of the window, ensure "Excel Add-ins" is selected in the Manage dropdown, and click Go...
4. In the pop-up box, check the "Analysis ToolPak" and click OK.

A new "Data Analysis" button will now appear on your Data tab.

Running and Reading the Regression

With the ToolPak enabled, you can now run the analysis:

1. Click the Data Analysis button on the Data tab.
2. Select Regression from the list and click OK.
3. For the "Input Y Range," select your metric data (e.g., cells B2:B13).
4. For the "Input X Range," select your time period data (e.g., cells A2:A13).
5. Choose an "Output Range" (an empty area on your worksheet where you want the report to appear) and click OK.

Excel will produce a summary table with a lot of data. For trend analysis, here are the most important numbers to focus on:

• R Square: This number (from 0 to 1) tells you how well the trendline fits the actual data fluctuations. A higher R Square (e.g., 0.92) means your data points are very close to the trendline, making the trend more reliable. A low value suggests there's a lot of volatility not explained by the simple trend.
• Intercept Coefficient: This is a starting point - the value of your trendline back at 'period zero'.
• X Variable 1 Coefficient: This number is the exact same as what you'd get from the SLOPE function. It's the calculated slope of your trend, showing the average increase or decrease per period.

Using regression gives you not just the trend itself, but a confidence score (R Square) in how predictable that trend really is.

Final Thoughts

From simple line charts to deeper statistical functions, Excel offers a comprehensive toolkit for uncovering trends in your data. Starting with a quick chart can give you instant visual insights, while functions like SLOPE and FORECAST.LINEAR provide solid numbers for planning and decision-making.

While mastering these Excel tricks can create powerful insights dashboards for business, you often still run into friction when your data is trapped in separate apps. We built Graphed because we wanted to eliminate the manual labor of connecting all that data. We connect directly to your marketing and sales tools like Google Analytics, Shopify, Facebook ads, and many more to bring your analytics together in dashboards and help uncover powerful insights. It's the most powerful AI analyst you can hire.