Konverteringar
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Omvandlare frÄn brÄkdelar av tum till mm.
Konvertera brÄkdelar av tum till millimeter och tillbaka. Skriv 3 1/4, 3-1/4, 1/4 eller 3,25 och fÄ ett exakt, förkortat brÄk.
Ange dina vÀrden
Resultaten uppdateras medan du skriver.
Hur man anvÀnder
One inch is defined as exactly 25.4 mm, so every conversion here is exact up Till the rounding you choose.
Accepted Iput formats: "3 1/4", "3-1/4", "1/4", improper fractions like "5/4", and plaI decimals like "3.25".
Resultats are always reduced â you get 1/2, never 8/16, and a value that rounds up to a whole inch reads as 1, never 16/16.
Pick 1/16 for framIg and general carpentry, 1/32 for cabIetry and joIery, and 1/64 for machIIg or fIe woodwork.
Vanliga frÄgor
How many millimetres are in an inch?
Exactly 25.4 mm. The international inch has been defined as precisely 25.4 millimetres since 1959, so inch-to-millimetre conversion is exact â the only approximation comes from rounding the fraction you read off a tape measure.
What input formats does this accept?
Mixed numbers with a space or hyphen ("3 1/4" or "3-1/4"), bare fractions ("1/4"), improper fractions ("5/4" = 1.25), and plain decimals ("3.25"). An inch mark or the word "in" on the end is fine too. Anything else returns a clear error rather than a silent wrong answer.
Why does it show 1/2 instead of 8/16?
Fractions are always reduced to lowest terms with a greatest-common-divisor step, so you get the form you would actually say out loud. For the same reason, a measurement that rounds up to a whole inch displays as "1", never "16/16".
Which precision should I choose â 1/16, 1/32 or 1/64?
1/16 in (1.59 mm) is the standard for framing, general carpentry and most tape measures. 1/32 in (0.79 mm) suits cabinetry, joinery and trim work. 1/64 in (0.40 mm) is for machining, metalwork and fine woodworking where a hair of slop matters.
How do I convert a decimal like 0.375 into a fraction?
Type it straight into the inches field. 0.375 in becomes 3/8 in (9.525 mm). The calculator rounds to your chosen denominator and then reduces, so decimals that land exactly on a fraction come out clean.