Unit Converter

What it's for

Turns one measurement into another: a length, an area, a volume or a weight. You enter one amount and get it in every unit of that category at once, so a metric dimension off a European spec sheet reads in feet and inches, or cubic feet of fill reads in yards. It converts only. There is no material list and nothing is checked against code.

Step by step

The screen opens on Length, feet and inches to millimeters, with nothing entered. The example converts an 8' 6" length to millimeters.

Unit Converter as it opens: the answer bar reads 0.00 mm with a sample tag and Feet & Inches: 0" under it. CATEGORY Length (Area, Volume and Weight beside it), FROM Feet & Inches (Millimeters beside it), AMOUNT 0" and TO Millimeters. RESULTS lists Feet & Inches: 0", Decimal Feet: 0.000', Inches: 0", Centimeters: 0.000 cm and Meters: 0.0000 m, all dimmed, with the link Check before you cut · Measure twice. — Steps 1–4, top to bottom, on the screen as it opens.

The AMOUNT keypad open over the Unit Converter, which is dimmed behind it and still shows 0.00 mm and AMOUNT 0". The sheet is headed AMOUNT with Done at the top right, 8' 6" typed above the keys, and the keypad has the digits, a decimal point, ft, in, a dash, a slash, backspace and an enter key. — Step 3: tap AMOUNT and the keypad comes up. Here 8' 6" is typed, ready for Done.

CATEGORY — pick Length, Area, Volume or Weight. The rows below change to suit.
FROM — the unit you have. For Length the choice is Feet & Inches or Millimeters.
AMOUNT — tap it and type the number. With Feet & Inches selected you type feet, inches and fractions the usual way, see Entering feet, inches and fractions. For the example, key 8 ft 6 in, then Done. With Millimeters, or in any other category, you get a plain number keypad, and the − and + beside the row nudge the amount by one.
TO — the unit you want as the headline. For Length the list is Feet & Inches, Decimal Feet, Inches, Millimeters, Centimeters and Meters.
Read the answer in the bar under the title. 8' 6" reads 2590.80 mm. The lines in RESULTS are the same amount in every other unit of the category.

The other categories

Area opens on 100 square feet to square meters, and offers Square Feet, Square Yards, Square Meters and Acres. Volume opens on 27 cubic feet to cubic yards, and offers Cubic Feet, Cubic Yards, Cubic Meters and Gallons (US). Weight opens on 100 pounds to kilograms, and offers Pounds, Kilograms, US Tons and Metric Tonnes. In these three, FROM and TO show all four units as buttons.

Reading the results

Unit Converter with AMOUNT 8' 6" and TO Millimeters. The answer bar reads 2590.80 mm with Feet & Inches: 8' 6" under it. RESULTS lists Feet & Inches: 8' 6", Decimal Feet: 8.500', Inches: 102", Centimeters: 259.080 cm and Meters: 2.5908 m. RESET has appeared beside the help button. — Step 5: the headline is the TO unit, 2590.80 mm. Every other unit is listed under it.

The headline, in the bar under the title, is your amount in the TO unit. The tag sample beside it means you have not entered anything yet. It goes once you enter an amount. The same sample tag beside CATEGORY, FROM or TO only says that choice is still the one the screen opened on.

The lines under it are the other units, each worked from the one amount you entered, so they always agree with each other. For 8' 6" they read 8.500' in decimal feet, 102", 259.080 cm and 2.5908 m. You rarely need to change TO just to see a different unit. It is already in the list.

The ≈ mark. Lengths are held exact. When a result cannot be written exactly in the places shown — a metric length written in feet and inches rarely lands on a sixteenth — the line starts with ≈. No mark means the figure is exact as written. Feet and inches are shown to the nearest 1/16". Area, volume and weight follow the same rule: 100 square feet reads ≈ 9.29 sq m (it is 9.290304), 27 cubic feet reads 1.000 cu yd exactly, and 100 pounds reads ≈ 45.36 kg. A small figure keeps three significant figures instead of rounding to nothing: 80 pounds reads ≈ 0.0363 t, and 0.0004 cubic yards reads ≈ 0.0108 cu ft.

This screen has no drawing, no materials list and no export buttons.

Common mistakes

Looking for inches or decimal feet under FROM. They are not there because the Feet & Inches keypad already takes them: type 30 for thirty inches, or 2.5 and the ft key for two and a half feet.
Cutting to a figure marked ≈ as if it were exact. It has been rounded to the places shown. Read the exact unit from the list if there is one.
Mixing up the tons. US Tons and Metric Tonnes are separate units in the Weight list. Check which one the supplier quotes.
Using it for an order. It converts a number. It does not add waste or round up to whole bags, sheets or yards. Use the calculator for the material, such as Concrete.