What is a Length Converter?
Screen sizes in inches, running distances in km, timber in feet: length units mix constantly, and approximations compound into real errors.
One input converts into every common metric and imperial unit at once, using exact definitions (1 inch = 25.4 mm).
Where the mixing actually costs something: sheet goods and pipe sold in feet against drawings in millimetres, screen diagonals in inches against the desk they have to fit, and distances where 10 km is 6.21 miles rather than the 6 people round it to. A 4 × 8 foot sheet is 1219 × 2438 mm, and a 32-inch monitor measures 81.3 cm on the diagonal: the number that decides whether it fits.
Frequently asked questions
How do I convert square feet to square metres?
Not on this page: it converts linear length only. Area conversions square the factor, so 1 sq ft is 0.3048² = 0.0929 sq m, and 1,000 sq ft is 92.9 sq m. Indian property listings quote both, and squaring the factor is the step people forget.
Why is a marathon 42.195 km?
Because the distance was fixed in imperial units: 26 miles and 385 yards, which comes to 42,194.99 m. The 5K and 10K were metric by design, so the marathon is the one common road distance left with an awkward number in both systems.
Are the factors exact?
Yes: the inch is defined as exactly 25.4 mm, and everything else derives from that and the meter.
Feet-and-inches input?
Convert the parts separately for now (5'10" = 5×30.48 + 10×2.54 cm): a combined input is planned.
Nautical miles?
Not yet: this covers everyday statute units.
How many decimals are shown?
Up to six meaningful digits; extreme values switch to scientific notation.