Excel: Steps Sample question:Find the area under curve in Microsoft Excel for the graph below, from x=1 to x=6.

Step 1: Choose a few data points on the x-axis under the curve (use a formula, if you have one) and list these values in Column A in sequence, starting from Row 1. In this example from the graph on the left, your x-values are 1,2,3,4,5 and 6. Ensure that the first and last data points chosen on the curve are its starting and ending points respectively. Step 2: List the corresponding y-axis data points in Column B, aligning them row-wise with the values in Column A. For this example, we’ll use y=1,0.5,0.33,0.225,0.2 and 0.19. Step 3: Type the following formula into cell C1 “=(B1+B2)/2*(A2-A1)” and copy this for all Column C cells till the second-last row of data. To copy, click cell C1 and then click and drag the little black box in the right hand corner. In this example, you have 6 data points so you would drag the formula to cell C5. Step 4: Calculate the sum of the totals in Column C. In this example, click cell C6 and then click the summation sign “Σ” on the ribbon. The solution will appear in cell C6. Step 5: Delete the last row in column c (not the total!–see the image below). The correct approximation will not show in the summation cell. For this example, the solution is 1.85.

That’s it! Tip: When finding the area under curve in Microsoft Excel, keep the x-axis increments as small as possible. This improves the curve’s approximation and the accuracy of the area under the curve. In other words, the more values you input into columns A and B, the more accurate your results will be. By using trapezoids of equal width, i.e. equidistant data points on the x-axis, you can do away with the first column; the formula in Column C is simply C1=(B1+B2)/2. The total sum of the values in Column C can then be multiplied by this constant width to give the total area under the curve.