Length converters
Length converters. One clear answer.
Start with the unit you have. Each calculator provides a decimal result, a ruler fraction with its rounding difference, and a table of useful reference lengths.
Millimeters →
Turn a metric measurement into decimal inches and a usable ruler fraction. See how much precision you lose when rounding to a tick mark.
MM → CMMillimeters to centimeters.Express small metric measurements in centimeters while preserving their millimeter detail.
MM → MMillimeters to meters.Turn a detailed drawing dimension into a room-scale length while keeping every millimeter in the calculation.
MM → FTMillimeters to feet.Translate a millimeter drawing dimension into a foot-based length without changing the underlying measurement.
Centimeters →
Read the decimal answer, find its nearest inch-ruler mark, and keep the rounding difference visible.
CM → MMCentimeters to millimeters.Move between centimeter readings and millimeter dimensions without losing the decimal part.
CM → MCentimeters to meters.Express heights and everyday dimensions in meters without losing the original centimeter detail.
CM → FTCentimeters to feet.Read a centimeter length as decimal feet or as whole feet plus the remaining inches.
Inches →
Convert a decimal, fraction, or mixed inch measurement into millimeters. No need to turn 2 3/8 into a decimal first.
IN → CMInches to centimeters.Translate inch measurements into centimeters, including mixed fractions from a tape measure.
IN → MInches to meters.Convert an imperial tape reading into a meter dimension, including mixed fractions such as 39 3/8.
IN → FTInches to feet.Split a long inch reading into whole feet and remaining inches, or keep it as a decimal-foot value.
Meters →
Convert a larger metric length into the fine units used on a cutting list or engineering drawing.
M → CMMeters to centimeters.Bring room-scale or fabric measurements into the centimeter units found on a tape measure.
M → INMeters to inches.Translate a metric length into decimal inches, then choose a fractional tick only if the job permits rounding.
M → FTMeters to feet.Express a room-scale metric length in decimal feet and a familiar feet-and-inches reading.
Feet →
Convert a decimal-foot length to centimeters and verify how the fractional foot relates to inches.
FT → MMFeet to millimeters.Convert foot-based stock lengths into millimeter dimensions for a metric cutting list.
FT → MFeet to meters.Convert a foot-based length into meters for metric forms, room plans, or dimensional comparisons.
FT → INFeet to inches.Turn a decimal-foot measurement into the total inches used in an inch-based specification.
Exact factors, sensible rounding
A meter contains 100 centimeters or 1000 millimeters. An international inch is exactly 25.4 millimeters, and a foot contains 12 inches. The calculators preserve those factors instead of relying on short approximations. The number of digits in an answer does not certify the accuracy of the source measurement.
Convert a number or measure an object?
Use a converter when you already have a length and need a different unit. Use the calibrated screen ruler when you have a small object but no measurement. For a longer object, use a tape measure or a checked printable ruler. These tasks have different sources of error, so a correct calculation alone cannot confirm an actual-size screen scale.
Decimal feet are not feet and inches
5.5 ft means five feet and half a foot: 5 ft 6 in. It does not mean 5 ft 5 in. A mixed measurement of 5 ft 3 in becomes 5.25 ft. Every calculator shows a separated feet-and-inches reading so that you can check this notation before using a converted dimension.
Useful without an account
All length calculations happen in your browser. Copy a result or share a calculation link containing the entered value and fraction precision. These query values do not create separate indexed pages. The formula, example, and reference table remain readable without JavaScript.
Know the limits
A nominal screw, pipe, or board size is not necessarily its measured diameter or finished dimension. Unit conversion does not establish compatibility, add cutting allowances, or remove manufacturing tolerances. For a fit, compare the relevant measured dimensions and their allowed tolerances rather than relying on a rounded fraction.
Reference: NIST unit conversion factors. Calculations use the international foot, not historical survey-foot units. Fractions are explicitly approximate. NIST ↗