Chart Axes

In all chart types except for pie and doughnut charts, Excel includes value and category axes by default. Certain chart types include a secondary values axis by default.

• Normal Chart - Values = Values()

• Normal Chart - X axis label = YValues()

• Scatter Chart - Values = Values()

• Scatter Chart - Y axis labels = YValues()

If the minimum is more than 5/6 of the maximum, then the Y axis will not start at zero.
For a bar or area chart it can be very misleading and you need to force the axis to start at zero

Automatic

Data with years in one column will be treated as dates and not as a category
In most cases, if your category-axis data consists of dates, Excel recognises that and will automatically apply the "time scaling" as opposed to the "category scaling" to the axis. Time scaling differs from category scaling in the following ways:

This calculation depends on the following:
1) the major unit specified in the scale tab
2) the minimum value
3) the maximum value

When all the numbers are positive, the maximum scale is the first major unit that is greater than or equal to the value returned by this expression:
MAX + 0.05 * (MAX - MIN)
otherwise the maximum scale is the first major unit greater than or equal to the maximum value
but if the difference between the maximum and minimum it greater than 16.667% of the maximum value, the minimum scale is zero.
but if the difference between the maximum and minimum is less than 16.667% of the maximum value, the first major unit that is less than or equal to the value returned by this expression:
MIN - ((MAX - MIN) / 2)
but if the chart is an xy-scatter or bubble chart the minimum scale is the first major unit that is less than or equal to the minimum value.
(taken from Microsoft's Product Support Services Web Site)

To eliminate any minor tick marks on your axes have the same number of minor units as major units.
Your tick marks should always be outside the axes and all axes should be labelled.
To move the x-axis labels to the bottom of a chart if negative numbers are displayed. (Format Axis > Patterns) (tick mark labels to "low").
If a chart should display a number on the x-axis and doesn't then you may need to stretch the chart a little, make it slightly wider.
You can copy a chart's data and formats to another chart. Select the chart, copy it, select the other chart and paste ??
To use the layout of the current chart for all new charts, select (Chart > Chart Type) and set as default on the Custom tab).
It is possible to have category labels that are numeric when you want to display yearly data.
If your category labels are numeric and you have a heading above it then Excel will automatically think that this is a separate series. To get round this problem, just remove the heading.
When a chart is selected the "Sheet tab" on the (File > Properties) dialog box changes to "Chart". This is obviously chart specific letting you change both size and quality when the chart is printed.
An XY Scatter chart is also commonly known as a scatter gram or scatter plot chart
A Gantt chart is a horizontal bar chart that is frequently used to provide a graphical illustration of a schedule and helps you coordinate and track specific tasks in a project.

It is possible that a chart can have two vertical axes. These are called values axes and each one can have a different scale.

Remember

The x-axis for a chart can have either a Category axis or Time Series axis. Even though it says time-scale it is really a date series as any time components in a date are ignore and midnight is always plotted ?? No partial days are considered.

Value Axis

Bounds - Minimum - The number at which the axis starts
Bounds - Maximum - The number at which the axis ends
Units - Major -
Units - Minor -
Horizontal axis crosses - Automatic -
Horizontal axis crosses - Axis value -
Horizontal axis crosses - Maximum axis value - When ticked the axis is positioned at the maximum value of the perpendicular axis.
Display Units - if your numbers are large numbers then you will want to display the values in terms of a unit.
Show Display Units Label on Chart - If you want the unit name to appear on the chart select
Logarithmic scale -
Values in reverse order - this means the scale extends in the opposite direction. Smallest values at the top and largest values at the bottom.

Major type -
Minor type -

Label position -

Category -
Format code -
Linked to source -

Excel 2010 and 2007

Axis Options tab

Minimum - Fixed - The number at which the axis starts.
Maximum - Fixed - The number at which the axis ends.
Major unit - Fixed - The size of the interval. The position for major gridlines.
Minor unit - Fixed - The position for minor gridlines.
Values in reverse order - This inverts the chart top to bottom. The category axis will also be changed from top to bottom.
Logarithmic scale -
Display units - Divides the numbers by a specific multiple of 10. Useful when the numbers have a lot of decimal places.
Show display units on chart - Adds the display unit label chart element alongside the axis.
Major tick mark type - Location of the major tick marks.
Minor tick mark type - Location of the minor tick marks.
Axis Labels - Location of the axis labels.
Horizontal axis crosses - automatic - Changes the intersection point of the axis.
Horizontal axis crosses - axis value - Changes the intersection point of the axis.
Horizontal axis crosses - maximum axis value - Changes the intersection point of the axis.

Number tab

Category -
Format code -
Linked to source -

Category Text

A category axis does not have a scale
The data is treated as a sequence of non-numerical text labels, and the marker is placed at a point along the axis according to its position in the sequence

Automatically select based on data -
Text axis -
Date axis -
Vertical axis crosses - Automatic -
Vertical axis crosses - At category number - (Value(Y) axis crosses at category number)
Vertical axis crosses - At maximum category - (Value(Y) axis crosses at maximum category)
Axis position - On tick marks -
Axis position - Between tick marks -
Categories in reverse order -

Interval between marks - The number of categories that are displayed between the tick marks (number of categories between tick marks)
Major type -
Minor type -

Interval between labels - Automatic -
Interval between labels - Specify interval unit - (number of categories between tick-mark labels)
Distance from axis - A small number to put labels close to the axis or a high number to move them further away
Label position -

Category -
Format code -
Linked to source -

Interval between tick marks - The size of the interval. The number of categories between each tick mark. The postion of the major gridlines.

Interval between labels - specify interval unit - The frequency of the axis labels.
Categories in reverse order - This flips the chart from left to right.
Label distance from axis - Location of the labels from the axis.
Axis type - Automatically select based on data - Automatic depending on the type of data.
Axis type - Text axis - Toggles the axis option settings between Text and Dates.
Axis type - Date axis - Toggles the axis option settings between Dates and Text.
Major tick mark type - Location of the major tick marks.
Minor tick mark type - Location of the minor tick marks.
Axis labels - Location of the axis labels. Drop-down containing Next to Axis
Vertical axis crosses - Automatic - Changes the intersection point of the axis.
Vertical axis crosses - At category number - Changes the intersection point of the axis.
Vertical axis crosses - At maximum category - Changes the intersection point of the axis.
Position axis - On tick marks -
Position axis - Between tick marks -

Category - Dates

Time Series Axis

The smallest possible unit is 1 day
If you want to display a smaller unit (time or fractional unit) then you need to use an XY Scatter chart
The time scale axis option is only available for the category axis.

Axis Type - Automatically select based on data -
Axis Type - Text Axis -
Axis Type - Date axis -
Bounds - Minimum -
Bounds - Maximum -
Units - Major -
Units - Minor -
Units - Base -
Vertical axis crosses - Between dates -
Vertical axis crosses - At date -
Vertical axis crosses - At maximum date -
Axis position - On tick marks -
Axis position - Between tick marks -
Dates in reverse order - Reverses the order of the series

Major type -
Minor type -

Label position - Drop-down containing Next to Axis

Category -
Type -
Locale -
Format Code -
Linked to source -

Minimum - The date at which the axis starts.
Maximum - The date at which the axis ends.
Major Unit - The size of the interval. The position for major gridlines.
Minor Unit - The position for minor gridlines.
Base Unit - The unit that is displayed on the axis.
Dates in reverse order - This flips the chart from left to right.
Axis Type - Automatically select based on data - Automatic depending on the type of data.
Axis Type - Text axis - Toggles the axis option settings between Text and Dates.
Axis Type - Date axis - Toggles the axis option settings between Dates and Text.
Major tick mark type - Location of the major tick marks.
Minor tick mark type - Location of the minor tick marks.
Axis labels - Location of the axis labels. Drop-down containing: Next to Axis,
Vertical axis crosses - Between dates - Change the intersection point of the axis.
Vertical axis crosses - At date - Change the intersection point of the axis.
Vertical axis crosses - At maximum date - Change the intersection point of the axis.
Position axis - On tick marks -
Position axis - Between tick marks -

The data is treated as continuously varying numerical data, and the marker is placed at a point along the axis which varies according to its numerical value.

Time Series data points are positioned in accordance with their chronological order
Time Series points are plotted in chronological order, whether or not the data range is sorted chronologically
Time Series data points use the smallest time period for their base unit, which typically defaults to 1 day

If you have the wrong dates on your axis it may be because your axis is set to automatic selection and therefore not on Category, from where you can select time-series.

Category MultiLine