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Entering feet, inches and fractions

You type a dimension the way you would say it out loud: whole feet, then inches, then the dash key before a fraction. The display follows every key, exactly — nothing is rounded.

Step by step

Five feet, three and a half inches is these eight keys:

The Dimensional Calculator keypad. The gold unit keys are the dash and slash in the fifth row and ft, in and # in the sixth row. The display shows a finished sum, 9' 9-15/16". 1 2 3 4 5
The gold keys build a dimension: ft, in, the dash and the fraction slash.
  1. 5 then ft — the whole feet.
  2. 3 — the whole inches.
  3. – the dash key. It says "the fraction starts here".
  4. 1 / 2 — the fraction.
  5. in — closes the dimension. The display reads 5' 3-1/2".

After feet or a fraction the in key is optional. You can go straight to + or = and the entry is read the same way.

Why the dash matters. Without it, 5, 1, /, 2 reads as fifty-one over two, not 5-1/2". The calculator refuses that entry and shows a red line at the bottom of the display: 51/2 is 25-1/2 · 5-1/2? key the dash. It gives the fraction's real value first, then the figure you probably meant. If you meant 5-1/2", press ⌫ back to the 5 and put the dash in; if you really meant fifty-one halves, type it as 25-1/2. The first-run intro shows these keys too: Settings ▸ ABOUT ▸ Show the intro again.

A number with no unit

A number typed with no ft, no in and no fraction is read as inches: 3 6 + is 36". A fraction on its own is inches too — 3 / 4 is 3/4". Press ft after it and it is feet: 1 / 3 ft is a third of a foot, 4".

The one exception is the number after × or ÷. Once the sum has a real dimension in it, that number is a count: 12' 6" ÷ 4 divides into four. The # key says "this is a plain number, not a length" wherever it sits. Type the digits, then #. See Parentheses and memory for how × and ÷ treat lengths and counts.

Decimals

The . key types a decimal into a whole number: 4.5 then ft is four and a half feet. A decimal cannot take a fraction — the dash and slash keys do nothing after a decimal point.

Filling in a calculator

Tap a field to open its keypad. Done or ↵ keeps what you typed. Next › keeps it and opens the next field down the form, so a slab's length, width and depth go in one after another. A field still at the example the calculator opened with carries a small sample tag after its name until you change it.

The ft and in keys after an answer

With a length answer on the display and nothing being typed, the unit keys switch how that answer is shown. in shows it in inches only, ft puts it back to feet and inches, and . shows decimal feet. The value does not change, only the way it is written. The calculator keeps your choice for later answers.

The precision chip

The chip at the bottom right of the keypad — it reads 1/16″ to start — sets the fraction answers are shown to. Tap it and pick from Nearest 1/2″ down to Nearest 1/64″. The same menu has the format: Feet & inches, Inches only or Decimal feet. The math underneath stays exact. When an answer does not land on the fraction you chose, the display marks it with ≈.

A number a field cannot take

A calculator's fields each take a range. Type a number outside it and the entry is refused, never changed: the keypad stays open, the field keeps what it had, and a red line names the range — Enter 10° to 170°. Fix the number, or tap Done with nothing typed to leave it as it was.

No calculator will work out a job from a zero either. Any length, size, spacing or count a calculator needs, left at 0, shows one line in place of its results — Enter a deck length greater than 0 — with nothing to buy, no code checks, no drawing and nothing to share or save. Where a 0 is a real answer it is kept: a deck at grade, a board gap of 0, a flat grade, a studio with 0 bedrooms.

The same goes for a size no one builds, too small or too big, and the line names the range — Enter a total rise from 8" to 50' 0":

Common mistakes

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