Article ID: 101939

Article Last Modified on 8/15/2003

APPLIES TO

- Microsoft Excel 97 Standard Edition
- Microsoft Excel 98 for Macintosh

This article was previously published under Q101939

## SUMMARY

This article explains how the automatic minimum and maximum limits for chart axis scales are computed in different versions of Microsoft Excel.

## MORE INFORMATION

In the following examples, the following names are used to describe certain values.

Name Description -------------------------------------------------------------------

yMax The maximum y value used in your chart.

yMin The minimum y value used in your chart.

xMax The maximum x value used in your chart. This applies only to charts that use x values, such as scatter and bubble charts. xMin The minimum x value used in your chart. This applies only to charts that use x values, such as scatter and bubble charts.

When you create a chart in Microsoft Excel, there are three possible scenarios that may apply to your data:

- The yMax and yMin values are both non-negative (greater than or equal to zero). This is Scenario One.
- The yMax and yMin values are both non-positive (less than or equal to zero). This is Scenario Two.
- The yMax value is positive, and the yMin value is negative. This is Scenario Three.

The major unit used by the y-axis is automatically determined by Microsoft Excel, based on all of the data included in the chart. The following scenarios use this default major unit.

### Scenario 1: Microsoft Excel 97 and Microsoft Excel 98 Macintosh Edition

In Microsoft Excel 97 and Microsoft Excel 98 Macintosh Edition, the following applies:

- If the chart is a 2-D area, column, bar, line or x-y scatter chart, the automatic maximum for the y-axis is the first major unit greater than or equal to the value returned by the following equation:

yMax + 0.05 * ( yMax - yMin )

Otherwise, the automatic maximum for the y-axis is the first major unit greater than or equal to yMax.

- If the difference between yMax and yMin is greater than 16.667 percent of the value of yMax, the automatic minimum for the y-axis is zero.
- If the difference between yMax and yMin is less than 16.667 percent of the value of yMax, the automatic minimum for the y-axis is the first major unit less than or equal to the value returned by the following equation:

yMin - ( ( yMax - yMin ) / 2 )

Exception: If the chart is an x-y scatter or bubble chart, the automatic minimum for the y-axis is the first major unit less than or equal to yMin.

### Scenario 1: All Earlier Versions of Microsoft Excel

In all earlier versions of Microsoft Excel, the following applies:

- The automatic maximum for the y-axis is the first major unit greater than or equal to yMax.
- If the difference between yMax and yMin is greater than 16.667 percent of the value of yMax, the automatic minimum for the y-axis is zero.
- If the difference between yMax and yMin is less than 16.667 percent of the value of yMax, the automatic minimum for the y-axis is the first major unit less than or equal to the value returned by the following equation:

yMin - ( ( yMax - yMin ) / 2 )

Exception: If the chart is an x-y scatter or bubble chart, the automatic minimum for the y-axis is the first major unit less than or equal to yMin.

### Scenario 2: Microsoft Excel 97 and Microsoft Excel 98 Macintosh Edition

In Microsoft Excel 97 and Microsoft Excel 98 Macintosh Edition, the following applies:

- If the chart is a 2-D area, column, bar, line or x-y scatter chart, the automatic minimum for the y-axis is the first major unit less than or equal to the value returned by the following equation:

yMin + 0.05 * ( yMin - yMax )

Otherwise, the automatic minimum for the y-axis is the first major unit less than or equal to yMin.

- If the difference between yMax and yMin is greater than 16.667 percent of the value of yMin, the automatic maximum for the y-axis is zero.
- If the difference between yMax and yMin is less than 16.667 percent of the value of yMin, the automatic maximum for the y-axis is the first major unit greater than or equal to the value returned by the following equation:

yMax - ( ( yMin - yMax ) / 2 )

Exception: If the chart is an x-y scatter or bubble chart, the automatic maximum for the y-axis is the first major unit greater than or equal to yMax.

### Scenario 2: All Earlier Versions of Microsoft Excel

In all earlier versions of Microsoft Excel, the following applies:

- The automatic minimum for the y-axis is the first major unit less than or equal to yMin.
- If the difference between yMax and yMin is greater than 16.667 percent of the value of yMin, the automatic maximum for the y-axis is zero.
- If the difference between yMax and yMin is less than 16.667 percent of the value of yMin, the automatic maximum for the y-axis is the first major unit greater than or equal to the value returned by the following equation:

yMax - ( ( yMin - yMax ) / 2 )

Exception: If the chart is an x-y scatter or bubble chart, the automatic maximum for the y-axis is the first major unit greater than or equal to yMax.

### Scenario 3: Microsoft Excel 97 and Microsoft Excel 98 Macintosh Edition

In Microsoft Excel 97 and Microsoft Excel 98 Macintosh Edition, the following applies:

- The automatic maximum for the y-axis is the first major unit greater than or equal to the value returned by the following equation:

yMax + 0.05 * ( yMax - yMin )

- The automatic minimum for the y-axis is the first major unit less than or equal to the value returned by the following equation:

yMin + 0.05 * ( yMin - yMax )

### Scenario 3: All Earlier Versions of Microsoft Excel

In all earlier versions of Microsoft Excel, the following applies:

- The automatic maximum for the y-axis is the first major unit greater than or equal to yMax.
- The automatic minimum for the y-axis is the first major unit less than or equal to yMin.

### X-axis Limitations

The above information also applies to charts that use x values, such as x-y scatter charts and bubble charts. For these types of charts, substitute xMax and xMin for yMax and yMin in the above scenarios.

Additional query words: XL98 XL97 XL7 XL5 4.00 4.0a 4.00a chartwizard XL

Keywords: KB101939