Convert any unit in one clean move

Yes, every category and conversion is free with no sign-up, no account, and no usage limit.

No account of any kind. There's no login and nothing to set up — open the page and the converter is ready immediately.

Yes. The layout, tabs, and converter are all built to work on a phone screen, not just desktop.

Any modern browser — Chrome, Safari, Firefox, Edge, and their mobile equivalents. It uses standard JavaScript and CSS with no plugins required.

Once the page has loaded, all conversions run locally in your browser. You'd only need a connection again to reload the page or fetch its fonts.

No. Every calculation happens in your browser with plain JavaScript — the numbers you type are never transmitted anywhere.

No. Nothing is saved between visits — the page always opens on the Length category with its default units.

The page uses standard form fields, labels, and buttons, which common screen readers generally handle well, though it hasn't been tested against every assistive technology.

Measurely uses standard internationally recognized conversion factors (1 mile = 1.609344 km, 1 pound = 0.45359237 kg, and so on) and computes results at full floating-point precision before rounding only the display.

The underlying calculation keeps full precision. What you see is rounded to up to six decimal places and trimmed of trailing zeros, purely for readability.

Small gaps usually come from rounding depth — some tools round early and carry the error forward. Measurely rounds only at the very end, which matters more for chained or repeated conversions.

Yes. This matters most for temperature, where negative values are common — for example converting −10°C to Fahrenheit works the same as any positive value.

Not reliably. Type plain digits with a period as the decimal separator, like 1500.5 rather than 1,500.5 or 1.5e3, so the field can read the value correctly.

Practically, no — the field handles anything from tiny decimals to very large numbers. At extreme magnitudes, ordinary floating-point precision limits apply, the same as any calculator.

No. The swap button flips which unit is the source and which is the target, but the number stays in the From field — the result is then recalculated for the new direction.

Covering both metric (mm, cm, m, km) and imperial (in, ft, yd, mi) units in one place means you rarely have to guess which system a figure was written in.

No — it's the standard statute mile (1,609.344 m) used for road distances. A nautical mile is longer (1,852 m) and isn't included as a separate Length unit, though the Speed category's knot is built on it.

Exactly precise — 1 mile is defined as exactly 1.609344 kilometers, so there's no approximation involved, only display rounding.

Yes. Millimeters, centimeters, and inches all convert with the same precision as larger units like kilometers or miles.

Feet and yards are both common in everyday and construction contexts in the US and UK — a yard is simply 3 feet, but having both saves you a manual multiplication.

It's a metric tonne (1,000 kg). A US short ton is a different, slightly smaller unit (about 907.18 kg) and isn't included as a separate option.

A stone equals 14 pounds and is the everyday unit for body weight in the UK and Ireland, which is why it's included alongside pounds and kilograms.

It uses the standard avoirdupois ounce (28.349523125 grams exactly), the same definition used for food labels and postal scales in the US.

A milligram is a very small fraction of a pound, so the result is naturally a small decimal — Measurely still calculates it at full precision before rounding the display.

No — like most everyday converters, it treats pounds, kilograms, and the like as equivalent measures of "how heavy something is," rather than separating mass from the physics concept of weight (a force affected by gravity).

Length, weight, and most other units share a zero point, so a simple multiplier works. Celsius, Fahrenheit, and Kelvin have different zero points, so they need a formula — Fahrenheit to Celsius, for example, is (F − 32) × 5⁄9.

Kelvin is the scientific temperature scale used in physics, chemistry, and astronomy, where 0 K is absolute zero. It's included alongside Celsius and Fahrenheit for lab and technical conversions.

The tool will calculate it mathematically — for example entering 0 K correctly shows −273.15°C — but it doesn't check whether a value is physically meaningful, so nothing stops you from typing an impossible number.

Celsius and Fahrenheit were defined using different reference points for freezing water, which is why the two scales don't line up at zero — converting between them always needs the offset-and-scale formula, not a simple multiplier.

US customary. A US gallon, quart, pint, cup, and fluid ounce are all noticeably smaller than their UK imperial counterparts, so double-check if you're converting a UK recipe or fuel figure.

A US cup is 236.59 ml, while a metric cup (used in Australia and some other countries) is a rounder 250 ml — close, but not identical, which can matter in baking.

128 US fluid ounces make up one US gallon.

You can convert the volume itself (liters to US gallons), though a full fuel-economy conversion like L/100km to MPG also involves a distance unit, which this tool handles separately under Length.

The Volume category focuses on the larger everyday and cooking measures — milliliters up through gallons — rather than the smaller spoon-based measurements.

A knot is one nautical mile per hour, used mainly in aviation and maritime navigation rather than everyday speed measurement.

They measure the same thing — distance per hour — just in different units. Most of the world uses km/h for road speeds, while the US and UK use mph.

m/s is the standard unit in physics and engineering, so it's included for technical calculations alongside the more familiar road-speed units.

Not directly — Speed converts rate units like mph and km/h, not a pace format such as minutes per mile. You'd need to convert your pace into a speed (miles or km per hour) first.

Both measure land area. An acre is a US and UK customary unit (about 4,047 square meters), while a hectare is the metric equivalent (10,000 square meters) — a hectare is roughly 2.47 acres.

About 10.76 square feet make up one square meter.

Square miles are the common unit for very large areas — counties, cities, or regions — where acres or hectares would produce unwieldy numbers.

Yes — Area covers the units most listings use, including square feet, square meters, acres, and hectares.

Measurely uses the binary convention: 1 KB = 1024 bytes, 1 MB = 1024 KB, and so on — matching how Windows and macOS typically report file and drive sizes.

MiB and GiB are the technically precise binary labels, but MB and GB are what most people actually see and search for, since that's what operating systems display. Measurely uses the familiar labels while calculating with the binary (1024-based) values behind them.

A byte is 8 bits. Network speeds are often quoted in bits (like megabits per second), while file sizes are usually quoted in bytes, which is a common source of confusion.

Because Measurely uses the binary definition throughout — 1 GB is treated as 1024 MB, and 1 MB as 1024 KB, consistent with how your operating system reports storage.

Yes — pick the Data category, enter the file size in one unit (like MB) and the drive's capacity in another (like GB) to compare them directly.

Months and years don't have a fixed length — months run 28 to 31 days and years vary with leap days — so a single multiplier would be misleading. Measurely sticks to units with a constant length: seconds, minutes, hours, days, and weeks.

Not as a combined value — enter the amount in a single unit at a time, such as 1.5 hours, and the equivalent in minutes or seconds will show automatically.

86,400 seconds make up one day.

The smallest unit currently available is seconds. Everyday time conversions rarely need finer resolution than that.

Yes. Each category — length, weight, temperature, volume, speed, area, data, and time — lets you pick any unit as the source and any unit as the target, not just one fixed pair.

The table always shows each category's most common default pair — for example miles to kilometers for Length — rather than whatever custom pair you've selected in the converter above.

No — switching categories resets the amount back to 1, since each category starts fresh with its own default pair of units.

No. The result updates automatically as you type or change a unit — there's no calculate button to press.

Yes. The amount field, unit dropdowns, and swap button are all standard form elements, so Tab, arrow keys, and Enter work as they would on any web form.

The "To" field always shows the calculated result. To convert in the other direction, use the swap button, which flips which side is the source and which is the target.