# Calc. Area Under Curve (Trapezoidal Rule) Excel & G Sheets

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## Calc. Area Under Curve (Trapezoidal Rule) Excel

There are several ways to calculate the area underneath a curve, but this example is going to show you how to do it using the Trapezoidal Rule.

**Starting with your Graph**

You’ll start with your base graph that shows the relationship between the X and Y Values. The goal is to find the total area underneath the curve on the graph.

**Starting with your Dataset**

Next, we have the dataset that we’re working with. In this case, Month is the **X Axis** and Sales is the **Y Axis**.

**Creating the Area Formula**

- Put in the following formula, which is a calculation to find the area under the line. As shown below, each individual formula shows the area under the graph between the data points. In this case, we type
**((Y Value 2) + (Y Value 1)) / 2 * (X Value 2 – X Value 1)**

2. Drag this formula down for data *except** the last data point*

3. In an empty cell below, sum all of the individual area formulas that you just calculated to find the area of the entire curve.

**Final Area under Curve**

After calculating the sum, the final sum will show the total area under the curve. In this case, we get a total area of **167.50**.

**How to Calculate Area Under Curve (Trapezoidal Rule) in Google Sheets**

In this case, calculating the area under the curve using the Trapezoidal Rule is the same in Google Sheets as in Excel. Use the same formula for the X and Y Values and you will be able to calculate the area under the curve.