# How to Use ConvertAll

## Contents

## Basics

Simply type a unit name in the "From Unit" edit window. As you type, the list below the window will be filtered to show only matching units. Matching unit names contain words starting with the words that are typed. Either type the complete unit name/abbreviation or hit the return key to use the unit highlighted (blue letters) in the list. Of course, clicking or tapping on a unit in the list will also add the unit to the edit window. You may also use the up and down arrow keys to highlight nearby units from the list.

Repeat the unit selection in the "To Unit" edit window. When done, if the units are compatible, the numeric edit windows below the unit lists will activate. A number may be entered into either numeric window and the other window will display the conversion result.

## Combining Units

The real strength of ConvertAll lies in its ability to combine multiple units. Simply type the unit names with an '*' or a '/' between them. This allows the entry of units such as "ft * lbf" or "mi / hr". The '^' symbol may be used for exponents, such as "ft^3" or "ft * lbm / sec^2". Negative exponents are allowed for units such as "sec^-1" (per second), but may switch the multiplication or division symbol ("ft * sec^-2" becomes "ft / sec^2").

Multiplication and division have the same precedence, so they are evaluated left-to-right. Parenthesis may also be used to group units in the denominator. So "m / sec / kg" can also be entered as "m / (sec * kg)". The version with parenthesis is probably less confusing.

Clicking or tapping on a unit from the list generally replaces the unit nearest the cursor.

The clear unit button in the header (lines with an X) may be used to empty the unit edit boxes to allow new units to be entered.

The filter List button in the header (funnel image) can be used to show only one type of unit in the list. Note that this doesn't show units that could be combined to form a type.

## Non-Linear Conversions

The conversion of some units is non-linear. Examples of these include the Fahrenheit and Celsius temperature scales (due to an offset zero point) and the American Wire Gauge (logarithmic). Non-linear units are labeled as such in the comments column.

These units can be converted only when they are not combined with other units or used with an exponential operator. Otherwise the conversion would not be meaningful.

## Shortcuts

When typing unit names, spaces are ignored, so they may be skipped. It is also generally ignored if a plural form of the unit name is typed. For squared and cubed units (positive exponents of 2 or 3) the "^" symbol does not need to be typed.

When a partially typed unit is highlighted in the list (blue lettering), hitting enter will complete the name. The up and down arrow keys can be used to highlight nearby units in the list prior to hitting enter. The unit closet to the cursor will be replaced.

The recent unit button in the header (clock image) opens a menu of recently used units and unit combinations. The entire current unit combination is replaced with selections from this menu.

The tab key can be used to cycle between the "From" and "To" unit test boxes and the "From" and "To" number editors.

The number to be converted may be entered in either the "From" or "To" unit side. Standard or scientific notation may be used, or an expression including the normal math operators (+, -, *, /) and parenthesis may be entered.

### Number Base Conversions

The "Bases" menu item brings up a dialog that can convert between various numbering system bases. There are entry boxes for decimal, hexadecimal, octal and binary. A number can be entered into any of the boxes and equivalents will be shown in the others.

The "Fractions" menu item brings up a dialog that can list fractional equivalents for a decimal number. Type the number and press enter. The fractions are listed in order of increasing accuracy.

## Options

The "Settings" menu item allows for changing several default options. These settings are automatically stored so that ConvertAll will re-start with the settings last used.

The first options control the display of numerical results, including the use of scientific notation and the number of decimal places. Be cautious about setting the number of decimal places to a low value, which can result in a significant loss of accuracy. Six places or higher is recommended (eight is the default).

There is an option to set the number of recent units to be saved. Setting it to zero will disable the recent unit button. Another option will automatically load the most recent previous units at startup.

The remaining options control appearances. The view scale ratio can be set to make the content smaller or larger (useful for high-dpi displays). The window size and position will be restored from the previous session use if enabled. The final setting selects between light and dark color schemes.