How to Do Trend Analysis in Google Sheets with ChatGPT

Staring at a wall of data in Google Sheets trying to spot a trend can feel daunting. You know the answers are in there somewhere - Is sales growth slowing down? Is that new marketing campaign actually working? - but turning rows and columns into clear insights takes time and spreadsheet expertise. This article cuts through the complexity by showing you how to use ChatGPT as your personal data assistant to perform trend analysis, generate formulas, and visualize your data directly within Google Sheets.

What is Trend Analysis?

Trend analysis is simply the practice of looking at historical data to identify patterns over time. Think of it as connecting the dots. Instead of just seeing that March sales were $15,000, trend analysis helps you see that sales have been consistently growing by 10% month-over-month for the past year. It's about spotting the bigger picture, not just individual data points.

Here are a few practical examples:

• E-commerce Store: Noticing a consistent spike in sales for outdoor gear every May, helping you plan inventory and marketing for the upcoming season.

• SaaS Company: Tracking monthly recurring revenue (MRR) and noticing that growth is accelerating after a key feature launch.

• Content Marketer: Observing that website traffic from organic search has been steadily climbing since you started focusing on blog content.

The goal isn't just to look backward. By understanding past patterns, you can make more informed forecasts and smarter business decisions for the future.

Step 1: Get Your Data Ready in Google Sheets

Before you bring ChatGPT into the mix, you need to set up your Google Sheets data in a way that's easy for an AI to understand. The saying "garbage in, garbage out" is especially true here. A clean, organized dataset is the foundation for any meaningful analysis.

Keep Your Data Tidy and Structured

Arrange your data in a simple table format. Each row should represent a time period (like a day, week, or month), and each column should represent a specific metric you're tracking. Stick to one table per sheet to keep things from getting confusing.

Use Clear, Descriptive Headers

Use simple, plain-English names for your columns. Instead of abbreviated or cryptic names like "Vis/Src_P," use clear headers like "Paid Traffic" or "Website Visitors." ChatGPT understands natural language, so clear headers provide crucial context.

For example, a good structure for monthly sales data would look like this:

Ensure Consistent Formatting

Make sure the data within each column is consistent.

• Dates: Use the same date format for every entry (e.g., MM/DD/YYYY).

• Numbers: Ensure values like sales or traffic are formatted as numbers, not text. You can select a column and go to Format > Number to fix this.

• Currency: Format monetary values consistently (e.g., $10,500, not a mix of "10500" and "$10,500.00").

Step 2: Ask ChatGPT to Create Google Sheets Formulas

Now for the fun part. You don't need to be a spreadsheet guru who has memorized every formula. You just need to describe what you want to achieve, and ChatGPT can generate the formulas for you. Treat it like you're asking a knowledgeable coworker for help.

Calculating Month-Over-Month Growth

Month-over-month (MoM) growth is a fundamental metric for tracking momentum. Instead of trying to remember the formula, just ask for it.

Example Prompt for ChatGPT:

"I have a Google Sheet with monthly sales data. Date is in Column A, and Total Sales is in Column B. Can you give me a formula I can put in cell C3 to calculate the month-over-month growth percentage based on the value in B2?"

Likely ChatGPT Response:

Of course! You can use this formula in cell C3:

=(B3-B2)/B2

After you enter the formula, just drag the little blue square at the bottom-right corner of the cell down the rest of the column to apply it to all your rows. Make sure to format the column as a percentage by going to Format > Number > Percent.

Finding a Moving Average to Smooth Out Data

Daily or weekly data can be noisy. A random spike or dip can make it hard to see the underlying trend. A moving average smooths out these fluctuations by averaging data over a specific period (e.g., the last 7 days).

Example Prompt for ChatGPT:

"I have daily website visitors in Column B of my Google Sheet, starting from cell B2. I want to calculate a 7-day moving average in Column C to see the weekly trend more clearly. What formula should I use in cell C8?"

Likely ChatGPT Response:

To calculate a 7-day moving average starting on the seventh day of data, you can use the AVERAGE function. Place this formula in cell C8:

=AVERAGE(B2:B8)

This formula averages the values from B2 to B8. You can then drag this formula down to calculate the moving average for each subsequent day.

Using FORECAST for Predictive Analysis

Want to take a look into the future? The FORECAST function in Google Sheets uses linear regression to predict a future value based on past data. It's great for simple "what-if" scenarios.

Example Prompt for ChatGPT:

"My Google Sheet tracks monthly ad spend (Column A) and the revenue it generated (Column B) for all of last year (cells A2:B13). Can you give me a Google Sheets FORECAST formula to predict how much revenue I might generate if I spend $5,000 next month?"

Likely ChatGPT Response:

Certainly. The FORECAST function is perfect for this. The syntax is FORECAST(x, data_y, data_x), where x is your new ad spend, data_y is your known historical revenue, and data_x is your known historical ad spend. Here's your formula:

=FORECAST(5000, B2:B13, A2:A13)

This formula will estimate the revenue based on the historical relationship between your ad spend and revenue.

Step 3: From Numbers to Narratives - Visualizing Your Trends

Numbers and formulas are powerful, but charts tell a story that your brain can process in seconds. While ChatGPT can't click the buttons in Google Sheets for you, it can act as an expert consultant, telling you exactly which chart to use and how to create it.

Choosing the Right Chart for Your Data

Not sure whether to use a line chart, a bar chart, or a pie chart? Just describe your data and your goal to ChatGPT.

Example Prompt for ChatGPT:

"I want to show how our total revenue has changed month-by-month over the last year. I also want to see the contribution of three different product lines to that total each month. What's the best chart type to use in Google Sheets?"

Likely ChatGPT Response:

A stacked column chart or a stacked area chart would be ideal for this. Both allow you to show the total revenue for each month and simultaneously see the breakdown of each product line's contribution. A stacked area chart is particularly good at emphasizing the total trend over time.

Getting Step-by-Step Instructions

ChatGPT can also act as your personal "help" menu, giving you instructions for more advanced tasks like adding a trendline to your chart.

Example Prompt for ChatGPT:

"I created a line chart in Google Sheets for my quarterly sales. How can I add a linear trendline to it to visualize the overall growth trajectory?"

Likely ChatGPT Response:

Sure, adding a trendline is easy:

1. Double-click on your chart to open the Chart editor panel on the right.

2. Go to the 'Customize' tab.

3. Expand the 'Series' section.

4. Scroll down, and near the bottom, you'll see a checkbox labeled 'Trendline'. Check it.

5. You can further customize its color, thickness, and type (linear, exponential, etc.) from here.

Step 4: Get Deeper Insights from Your Data

Beyond generating formulas, you can have a conversation with ChatGPT about your data. By copying and pasting a small summary table from your sheet, you can ask for interpretations, spot anomalies, and even brainstorm ideas.

First, compute your key metrics like month-over-month growth. Then, copy that summary table (e.g., two columns: Month and MoM Growth %) and paste it into ChatGPT.

Now, you can ask interpretive questions:

• "Here is my website traffic data for the last 6 months. [Paste data] What trends or patterns do you notice? Are there any standout months I should investigate?"

• "Sales growth slowed down significantly from May to June. [Paste data] Based on this, what are some common business reasons this might happen that I should look into?"

• "Based on the consistent growth trend in the last quarter, what would be a reasonable but ambitious sales projection for Q4?"

This transforms ChatGPT from a simple calculator into a brainstorming partner, helping you connect the 'what' to the 'why'.

Important Caveats: Privacy, Accuracy, and Live Data

Using ChatGPT for data analysis is incredibly powerful, but you need to be smart about it.

Data Privacy: Never paste sensitive personal, financial, or proprietary information into a public AI tool like ChatGPT. Your chats can be reviewed or used for training. Always work with aggregated, anonymized data for these exercises.

Verify Everything: ChatGPT can occasionally make mistakes or "hallucinate" incorrect formulas. Always test the formulas it provides on a small section of your data to ensure they work as expected before applying them to your entire dataset.

Static Analysis: Remember, this process provides a static snapshot of your data. The analysis is only as current as the data you've manually entered or exported into your Google Sheet. If your data changes daily, this manual process can quickly become tedious.

Final Thoughts

This method of combining Google Sheets and ChatGPT empowers you to perform sophisticated trend analysis without needing an advanced degree in data science. You’ve learned how to properly structure your data, ask for complex formulas in plain English, choose the right visualizations, and even interpret the results you find. It’s an amazing leap forward for anyone who has been intimidated by spreadsheets.

While this is a fantastic way to handle one-off analyses, the process of exporting data, copying, pasting, and manually updating can become a major time-drain for ongoing team reporting. We built Graphed to solve this exact problem. Instead of working between tabs, you connect your data sources directly (like Google Ads, Shopify, or Salesforce) and use simple natural language prompts to create live dashboards that update in real-time. It completely removes the manual busywork, allowing you and your team to focus on making decisions, not on building reports.