Unit Converters.

Metric and imperial units coexist throughout everyday professional and personal life. An engineering specification in millimetres needs to be read alongside a drawing in inches. A recipe calls for cups and Fahrenheit but you work in grams and Celsius. A shipping manifest lists weights in pounds but your system expects kilograms. Unit conversion should be instant and exact — not a source of rounding errors or unit confusion that introduces downstream mistakes.

The Length Converter converts between millimetres, centimetres, metres, kilometres, inches, feet, yards, miles, nautical miles, and light years. Enter a value in any unit and all others update simultaneously. Architects, engineers, manufacturing teams, and anyone working across measurement systems use this daily to validate dimensions and translate specifications.

The Weight and Mass Converter handles milligrams, grams, kilograms, metric tonnes, ounces, pounds, and US short tons. Used for shipping weight calculations, nutritional label reading, recipe scaling, and any context where metric and imperial mass units need to be reconciled. The conversion factors are exact, not approximations.

The Temperature Converter converts between Celsius, Fahrenheit, and Kelvin simultaneously. Celsius and Fahrenheit cover everyday use — cooking, weather, body temperature. Kelvin is the SI base unit for thermodynamic temperature and is essential for scientific and engineering work involving absolute temperature. All three scales update when you type in any field.

The Time Converter translates between seconds, minutes, hours, days, weeks, months, and years. Most useful for software development work involving timeout values, TTLs, and cache durations — where you need to confirm that "86400 seconds" and "1 day" are the same thing — as well as for scientific calculations and everyday duration math.

All unit converters use precise conversion factors computed entirely in your browser. There are no server round trips, no data collected, and no account required.

Frequently Asked Questions

How accurate are the unit conversions?

The converters use standard, exact conversion factors — for example, 1 inch is defined as exactly 25.4 millimetres, and 1 pound is exactly 453.59237 grams. Results are computed using JavaScript's 64-bit floating-point arithmetic, which is accurate to 15–17 significant digits for most conversions.

Does the length converter support nautical miles?

Yes. The length converter includes nautical miles (1 nmi = 1852 metres exactly) alongside the other distance units. It also includes light years for astronomical-scale distances.

Can I convert between Kelvin and Celsius?

Yes. The temperature converter handles all three scales simultaneously — Celsius, Fahrenheit, and Kelvin. The relationship is: K = °C + 273.15. Absolute zero (0 K) equals −273.15 °C.

How many days does the time converter use for a month?

The time converter uses 30.4375 days per month (the average Gregorian month length: 365.2425 days per year ÷ 12). This is an average and not calendar-exact — for precise date arithmetic, use a calendar tool instead.

Do these converters work offline?

Once the page has loaded, the converters work without an internet connection. All calculations run in your browser using JavaScript. No network requests are made when performing conversions.

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