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

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Editorial Team

Reviewed by

Steve Rynearson

Last updated on October 30, 2023

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.

Excel Trapezoidal Rule Area


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.

Dataset to find Area under Curve in Excel


Creating the Area Formula

  1. 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)

Trapezoidal Formula for Area under Curve


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

Calculating Area for Trapezoidal Area in Excel


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.

Total Area Under Curve Using Trapezoidal Formula


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.

Dataset to find Area under Curve in Graph Excel


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.


Calculate Area under Curve Google Sheets

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