How Do You Find the Area Under a Curve Using Excel?
To find the area under a curve using Excel, list the xaxis and yaxis values in columns A and B, respectively. Then, type the trapezoidal formula into the top row of column C, and copy the formula to all the rows in that column. Finally, determine the sum of the values in column C to find the area.

List the xaxis values
In the A column, list the xaxis values of the graph using equal intervals, ensuring the use of the first and last data points. Increase the number of intervals listed to increase the accuracy of the final answer.

List the yaxis values
In column B, list the yaxis values that correspond with the aligning xaxis value.

Enter the trapezoidal formula
In column C, type in the following formula in the row corresponding with the first xaxis value: =(A2A1)*(B1+B2)/2. The row numbers for both sets of values correspond with the starting row of the data points. Fill in all the rows in column C with this formula by clicking the box’s fill handle and dragging down to the last row.

Calculate the area
Delete the value in the last row of column C, then find the area by calculating the sum of column C. In an empty cell, type in =SUM(C1:C?), the question mark representing the number of the last row. The answer is the estimated area under the curve.