Unit Converter

Choose a category, enter a value, and select source and target units. The result updates on this page so you can check everyday measurements.

This browser could not start the converter. Open this page in a browser that supports JavaScript modules. The guide and unit list below remain available.

Result

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How to use it and limits

Enter up to 64 characters, including leading and trailing spaces. Zero is accepted; a non-zero value must have an absolute value from 1e-12 through 1e12, inclusive. Shorten a value that exceeds the length limit. Length, area, mass, and volume must be non-negative. Temperatures cannot be below absolute zero.

Conversions use fixed factors and browser floating-point arithmetic. Results show at most 12 significant digits; displayed precision is not the precision of the original measurement. Reloading the page clears the input.

Supported categories and units

Length: millimetres (mm), centimetres (cm), metres (m), kilometres (km), inches (in), and feet (ft).
Area: square centimetres (cm²), square metres (m²), square kilometres (km²), and hectares (ha).
Mass: milligrams (mg), grams (g), kilograms (kg), and avoirdupois pounds (lb).
Volume: millilitres (mL), litres (L), and cubic metres (m³).
Temperature: degrees Celsius (°C), degrees Fahrenheit (°F), and kelvins (K).

Convert in four steps

Choose length, area, mass, volume, or temperature.
Enter the value. A blank field stays empty; it is not treated as zero.
Choose the source and target units. Swap units keeps the entered value and exchanges the two units.
Read the live result and formula. They update when the value or either unit changes.

Number format and result range

Enter ASCII digits, an optional leading sign, a decimal point, or scientific notation, such as 12.5, .5, 1., or 1.25e2. Leading and trailing ASCII whitespace is ignored.
Thousands separators, full-width digits, expressions, hexadecimal values, NaN, and Infinity are rejected.
Length, area, mass, and volume accept non-negative values only. Temperature inputs are temperature values, not temperature differences. The lower bounds are -273.15 °C, -459.67 °F, and 0 K.
A result must remain in the supported range: its absolute value cannot exceed 1e18, and a non-zero result must be at least 1e-18 in absolute value. If the result is out of range, the previous result is cleared.

How your data is handled

Conversion runs in this page's browser. The tool uses the input only in page memory and does not actively write it to browser storage or upload it. Reloading clears the current value. A website host may still receive the connection information needed for an ordinary page request.

Frequently asked questions

Can I convert currencies or exchange rates?: No. The converter supports only the fixed units listed above; it does not provide exchange rates or other live data.
Are the results exact?: Conversions use fixed factors and browser floating-point arithmetic. The display shows at most 12 significant digits, which does not represent the precision of the original measurement.
Can I convert a temperature difference from Celsius to Fahrenheit?: No. The temperature field represents a temperature value, so it cannot be used to convert temperature differences.
Is my input saved or uploaded?: The tool does not actively save or upload input. The value is used in page memory for the current conversion, and reloading the page clears it.
Can I enter a negative temperature?: Yes, as long as it is not below absolute zero in the source unit. Length, area, mass, and volume accept zero or positive values only.
Can I enter 1,000 or a math expression?: No. Enter one ASCII decimal number or a value in scientific notation. Commas, full-width digits, and expressions are not accepted.