QuickMetric initially launches with the “Choose a conversion:” screen and waits for a selection. After the first use, QuickMetric will return to the most recent state at launch. The “Choose a conversion” screen can always be brought back with one press of the custom “QM” button at the bottom left of the screen.

Basic Input and Output

On touching a selection, the program immediately transitions to the numeric entry mode, ready for input. Either side (gray or red) can be pressed at any time to allow entry of another number, and this selection will become the default for the next conversion. After pressing “Convert”, the next number for a similar conversion can be entered immediately.

The screen is arranged with the main entry and conversion in the upper blocks, with relevant equivalents displayed below if appropriate. The equivalents respond in context, often with smaller units for  small input, and larger units for larger input (e.g. When entering pounds ↔ kilograms, ounces and grams are displayed for entries under ten pounds, while short tons and tonnes are displayed for values over 400 pounds.)

The keypad takes a large area of the screen, allowing quick entry. Touch the gray or red blocks to select an entry area, then type the number on the keypad. The decimal is a special key, briefly changing into a “−” key for temperature conversions only (and changing right back into a decimal to allow regular input). The large Red “C” button clears the display. Note that pressing the upper gray or red blocks directly clears the display as well, and that choice becomes the new default.

Display precision can be selected as regular (adjusts for context and is suitable for general use) or maximum, which makes use of up to 6 decimal places.

Pressing the custom “QM” button at the bottom left of the display will return to the “Choose a conversion” screen at any time.

Fractions for US Units

Most US units can have fractions added after the main quantity has been entered. Pressing the [+ fraction] key allows the numerator to be entered. The denominator can then be selected from a range of 1/2 to 64ths.

100+ Line Review and Saving Lists

The small black [view] button at the bottom center of the screen transitions to a scrolling review of conversions from the present session. This list can be edited (touch within the list) and saved to one of three retained list memories (L1, L2, L3). In addition, by using the copy and paste functionality of the new iPhone OS, it is possible to copy sections of a list into another larger list and save.

Visualizer Bars

When the keypad screen displays, gray and red display bars typically appear at the bottom left. These bars present the relative size of the US and metric units for reference.

The only conversion where these are not relevant is “MPG ↔ l/100km”, as this is an inverse relationship (the more miles per gallon, the less fuel that is burned to go a given distance).