"Feet & Inch" Unit Display Defined in SolidWorks

The following is intended to provide a more detailed outline of what your
dimensions will look like if you use “Feet & Inches” for your units.
You can change your display units by going to “ToolsOptionsDocument
PropertiesUnitsCustom – Feet & Inches.”

Here is a default “IPS (inch, pound, second)” display.  SolidWorks is using the values from columns A and B.

We now want our UNITS to display as “Feet and Inches”.

First, we must set “Unit System” to “Custom” then column A to “feet & Inches”.

As you can see, 13.2150 changes to a feetdecimal format…. 1′ 1.2150.”

COLUMN C:

Column C
is a Denominator or number of total pieces a whole is divided into.
IE, Cut a pie in 4 slices, the denominator is 4.  The decimal
equivalent would be 0.250.

If we set column C – Fractions to a value (i.e., 4), the 13.2150 does not change to a fraction.  That is because the decimal value is not a divisible fractional value of 1/C value.  Because C = 4,
the decimal would need to be 13.25, 13.50 or 13.75.  Then it would
switch to 1′ 1-1/4″, 1′ 1- 1/2″ or 1′ 1-3/4″ respectively.

COLUMN D:

If you ALWAYS want a decimal value to display as a fraction, (excluding whole numbers), you need to set column D to “Round to nearest fraction.”

**
Important to note, if you input a value of say 1.200″, it will display as 1
1/4.” This is only graphical.  The TRUE length of it is still 1.200.”
It’s just rounding the display value.

In this case, C = 4 => 1/4 => 0.2500

With our initial length being 13.215 and C evaluating every .25″, the evaluation range is  13.25 — 13.215 –13.00.

Thus 13.215 is within .035 of 13.25 so it rounds up to 1/4″.

This results in the 1′ 1- 1/4″ Value.  The larger C is, the closer the fractional display will be to the actualtrue line length.