Start with the right category
A pound is mass, a psi is pressure, and a fluid ounce is volume. Choose what the number measures before choosing the unit.
10 categories · 80+ units
Convert the number.
Keep the context.
Fast everyday conversions with clear units, sensible precision, and no mystery math.
01
Type on either side.
The other updates instantly.
The converter
What are you measuring?
Values stay in your browser
Quick reference
Common length conversions
Tap a row to use that value.
Use it well
A converter is simple.
The details still matter.
Unitwise converts through a consistent base unit for each category. That makes it easy to compare metric, U.S. customary, and specialist units without stacking rounded shortcuts on top of one another.
Watch the local convention
This tool labels U.S. cups, pints, quarts, gallons, and fluid ounces explicitly. Imperial volume units are different and should not be treated as interchangeable.
Round for the job
The calculator preserves precision, but real measurements are only as exact as the original value. For everyday use, two to four decimal places are usually enough.
Worked examples
Three useful distinctions
Small labels prevent surprisingly large mistakes.
5 km → 3.1069 mi
Distance
One international mile is exactly 1,609.344 meters, so five kilometers is a little more than three miles.
350°F → 176.67°C
Temperature
Temperature scales need an offset as well as a ratio. That is why temperature cannot be converted with a single multiplier.
2 GiB → 2.1475 GB
Digital storage
GiB is binary: 230 bytes. GB is decimal: 109 bytes. They sound similar, but they are not the same size.
Questions, answered
Before you rely on the number
How accurate are these conversions?
Calculations use full browser numeric precision, then display up to ten significant digits. Physical unit factors are based on published NIST references. Your result cannot be more certain than the measurement you entered.
Why does Unitwise say “weight & mass”?
Pounds and kilograms are units of mass, although people commonly call both “weight” in everyday conversation. True weight is a force and changes with gravity; ordinary shopping, cooking, and body-weight conversions generally mean mass.
Are the cups and gallons U.S. or Imperial?
They are U.S. customary units and are labeled “US” in the selector. An Imperial gallon is larger than a U.S. gallon, so check the source of a recipe or measurement before converting.
What is the difference between MB and MiB?
One MB is 1,000,000 bytes. One MiB is 1,048,576 bytes. Storage manufacturers usually use decimal units such as GB, while some operating systems and technical tools use binary units such as GiB.
Does the site save what I type?
No. Conversion values are calculated in your browser and are not stored or sent to Unitwise. Advertising and hosting providers may process technical data as described in the privacy policy.
Can I use this for professional or safety-critical work?
Use Unitwise as a convenient reference, not as a substitute for the standards, calibration, significant-figure rules, or professional review required in medical, engineering, scientific, legal, or safety-critical work.
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