How to Create a Bell Curve in Excel

A bell curve in Excel uses a formula and chart, not a built-in button

A bell curve (also called a normal distribution curve) is a graph that shows how data spreads around an average. To create one in Excel, you build a column of numbers using the NORM.DIST function, then chart those numbers as a line graph. It takes about five minutes once you know the steps.

Excel does not have a "bell curve" tool you click. Instead, you create the mathematical data the curve needs, then tell Excel to draw it. This matters because it means you control what the curve shows — you can adjust the average, the spread, or the range of values to match your actual data.

Key Takeaways

A bell curve requires two things: a column of X-axis values (usually numbers from roughly -4 to +4) and a column of Y-axis values calculated using the NORM.DIST function.
The NORM.DIST function takes four inputs: the X value, the mean (average), the standard deviation (spread), and FALSE to get the height at that point rather than the cumulative total.
After you have both columns filled, select them both and insert an XY Scatter chart, then change the line style to smooth to get the curved shape.
You can adjust what the curve shows by changing the mean and standard deviation numbers — higher standard deviation makes the curve wider and flatter.

Set up your X-axis values in the first column

Start in cell A1 and type a header like "X Value". In A2, type -4. In A3, type -3.9. Select both cells, then drag the fill handle (the small square at the bottom right of the selection) down to row 102. Excel will auto-fill the sequence, stepping by 0.1 each time, until you reach 4.

This gives you 101 data points spread evenly across the range where the bell curve has visible height. If you want a smoother curve, use smaller steps like 0.05 instead of 0.1 — that means more rows, but a rounder shape. If you want fewer points to work faster, use 0.2 or 0.5.

Create the Y-axis values using NORM.DIST

In cell B1, type a header like "Probability". In B2, type this formula: =NORM.DIST(A2,0,1,FALSE)

This formula means: take the X value in A2, assume the average (mean) is 0, assume the spread (standard deviation) is 1, and give me the height of the curve at that point (FALSE means don't give me the cumulative total). Press Enter. The cell will show a number like 0.054 — that is the height of the curve at X = -4.

Now copy this formula down the entire column. Click B2, then drag the fill handle down to B102 (or however many rows you filled). Excel will automatically adjust the A reference for each row — B3 will use A3, B4 will use A4, and so on. You now have 101 Y values that follow the bell curve shape.

Insert an XY Scatter chart

Select both columns A and B, including the headers. Go to the Insert tab and click Chart. Excel will open the chart wizard. Choose XY (Scatter) as the chart type — not Line, not Column, but Scatter. This matters because Scatter charts let you control exactly how the line connects the points.

In the chart wizard, look for the option that shows a line connecting the points (usually the second or third option under XY Scatter). Click Next and finish the wizard. Excel will create a chart, but it will look jagged and angular because it is connecting straight lines between points.

Smooth the line to create the curve shape

Double-click the chart to enter edit mode. Right-click the line itself (the jagged line connecting your data points) and select Format Data Series. Look for a Smoothing option or Line Style setting. In newer versions of Excel, this is under the Line tab. Check the box for "Smoothed line" or set the line to "Smooth" rather than "Straight".

Click outside the chart. The line will now curve smoothly instead of zigzagging. This is your bell curve. The shape should be symmetric — higher in the middle, lower on both sides, with the peak at X = 0 (because you set the mean to 0).

Adjust the curve by changing the mean and standard deviation

The formula you used was NORM.DIST(A2,0,1,FALSE). The second number (0) is the mean — the center of the curve. The third number (1) is the standard deviation — how wide the curve spreads. You can change these to match your actual data.

If you want the peak to be at 100 instead of 0, change the formula to =NORM.DIST(A2,100,1,FALSE). If you want the curve wider and flatter (showing more variation), change the 1 to 2 or 3. If you want it narrower and taller (showing less variation), change it to 0.5. Copy the new formula down the column and the chart updates automatically.

Common reasons your bell curve looks wrong

If your curve looks like a flat line or a thin spike, you probably used the wrong chart type. Go back and check that you chose XY Scatter, not Line or Column. If the line is still jagged after you explore smoothing, you may not have enough data points — try using 0.05 steps instead of 0.1.

If the curve is not centered where you expect, check the mean value in your NORM.DIST formula. If it looks too flat or too tall compared to what you want, adjust the standard deviation. There is no single "correct" shape — it depends on what your data actually shows.

Frequently Asked Questions

Can I use my own data to create a bell curve instead of making one from scratch?

Yes. Calculate the mean (average) and standard deviation of your data using AVERAGE() and STDEV() functions. Then use those numbers in the NORM.DIST formula instead of 0 and 1. This shows what a perfect bell curve would look like if your data followed a normal distribution.

What does the FALSE in the NORM.DIST formula do?

FALSE tells Excel to give you the probability density (the height of the curve at that point). If you use TRUE instead, you get the cumulative probability (the total area under the curve up to that point), which creates a different shape entirely — an S-curve, not a bell.

Why does my bell curve have a different height than someone else's?

The height depends on the standard deviation. A standard deviation of 1 creates a taller, narrower curve. A standard deviation of 2 creates a shorter, wider curve. Both are correct — they just show different amounts of variation in the data. The total area under any bell curve is always 1.

Can I add a title or labels to my bell curve chart?

Yes. Double-click the chart to edit it. Right-click the chart title area and select Edit Title, or go to the Chart Design tab and click Add Chart Element. You can add a title, axis labels, and a legend. Make sure your axis labels explain what the X and Y values represent.

Do I have to start at -4 and end at 4 for the X values?

No. Those numbers work well because they cover about 99.7% of the data in a standard bell curve. If your mean is 100 and standard deviation is 10, you could use X values from 70 to 130 instead. The shape stays the same — only the scale changes.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.