Unit Converter

Length, weight, volume and area — metric ↔ imperial

Conversion

3.2808399
1 m
3.2808399 foot

About

Convert between metric and imperial units for length, weight, volume, and area. Enter a value, pick the source and target units, and read the converted result. Everything runs in your browser.

    Examples

    Convert 100 kilometers to miles

    Input
    category: Length
from: kilometer (100)
to: mile
    Output
    100 km = 62.137 mi

    Uses the exact 1 km = 1/1.609344 mi definition, so the result is reproducible to the last decimal.

    Convert 5 kilograms to pounds and ounces

    Input
    category: Weight
from: kilogram (5)
to: pound, ounce
    Output
    5 kg = 11.023 lb = 176.37 oz

    The same input maps to multiple imperial units at once, useful for shipping forms that mix unit systems.

    About this tool

    Unit Converter translates values across four measurement categories — length, weight, volume, and area — with full coverage of both metric and imperial units. Conversions are bidirectional, so you can enter either side of the pair and read the result in the other.

    All factors come from the standard SI-based definitions, so results match what you would get from NIST SP 811. Conversion runs entirely in your browser; your values never leave your device.

    How to use

    1. Pick a category

      Choose length, weight, volume or area from the category selector to load the supported units.

    2. Enter a value

      Type a number in the From field and pick its unit. The result appears instantly in the To field.

    3. Adjust precision

      Set the number of decimal places shown so the output matches the precision your use case needs.

    Use cases

    Converting between metric and imperial

    Quickly translate a recipe, a measurement, or a data sheet from one unit system to the other without launching a separate calculator.

    Validating internationalized forms

    Confirm that a back-end conversion of a user-entered value matches the expected output before shipping to production.

    Teaching unit conversion

    Show the exact conversion factor in use (e.g. 1 inch = 2.54 cm exactly) so learners see that 'rounded' values are not the underlying numbers.

    Common mistakes

    Mistake:Treating avoirdupois ounces and fluid ounces as the same.

    Fix:They measure different things — weight vs. volume. The category selector picks the right conversion; mixing the two produces nonsense results.

    Mistake:Conflating short tons, long tons, and metric tons.

    Fix:A US short ton is 2000 lb, a long ton is 2240 lb, and a metric ton is 1000 kg. Always check which ton a document refers to before converting.

    Mistake:Rounding intermediate steps.

    Fix:Each conversion carries rounding error. Convert once in the most precise direction, then round only the final displayed value.

    Frequently asked questions

    References & standards

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