Seven Kinds of Units, One Converter
The world never agreed on units, so conversion is a permanent fact of life: recipes in cups meet kitchens in grams, running apps speak kilometers to mile-thinkers, weather reports cross the Celsius–Fahrenheit border, and cloud invoices bill gigabytes against disks sold in gibibytes-by-another-name. This converter covers the seven categories that account for nearly all real-world need — length, weight/mass, temperature, volume, area, speed and digital storage — with precise factors, instant as-you-type results, and conversion in both directions.
How to Use It
- Pick a category tab: length, weight, temperature, volume, area, speed or data.
- Choose the from-unit and to-unit from the dropdowns — metric, imperial and the common specialty units are all present.
- Type a value in either field; the other updates live. Swap direction with one click.
The Conversions People Need Most
- Length: kilometers ↔ miles (1 km ≈ 0.621 mi), meters ↔ feet, centimeters ↔ inches (2.54 cm = 1 in, exactly — one of the few exact definitions).
- Weight: kilograms ↔ pounds (1 kg ≈ 2.205 lb), grams ↔ ounces — the recipe-rescue pair.
- Temperature: Celsius ↔ Fahrenheit ↔ Kelvin — the only category where conversion is not a simple multiplication, because the scales have different zero points: °F = °C × 9/5 + 32.
- Volume: liters ↔ gallons (mind the species: a US gallon is 3.785 L, an imperial gallon 4.546 L — labeled separately here because confusing them is a classic costly error), milliliters ↔ cups.
- Area: square meters ↔ square feet, hectares ↔ acres — real-estate arithmetic across systems.
- Speed: km/h ↔ mph ↔ knots ↔ m/s.
- Data: KB/MB/GB/TB with the decimal (1000) and binary (1024) conventions both available and clearly labeled — the honest explanation of why a “1 TB” drive shows ~931 “GB” in your operating system.
Precision, Stated Plainly
Conversions use the internationally defined factors — many of which (the inch, the pound, the US gallon) are exact definitions against metric, not approximations. Results display sensible precision for reading while the underlying computation keeps full floating-point accuracy, and the copy button grabs the unrounded value. Temperature converts through the proper affine formulas, including below-zero and Kelvin cases. For digital storage, both conventions are first-class citizens because both are genuinely in use: marketing and SI say 1 GB = 10⁹ bytes; operating systems and memory engineering count 2³⁰ — neither is wrong, and the labels here keep you certain which one you are getting.
A Tool That Rewards Being One Click Away
Unit conversion is never the task — it is the small obstacle inside every other task: the recipe, the workout, the purchase, the homework, the spec sheet. That is why this page is built for speed: no submit button, both directions live, categories one tap apart, all computation local to your browser with nothing transmitted and full offline operation once loaded. Bookmark it once and the cups-to-grams question never costs more than five seconds again.
Why Precision Habits Matter
Most daily conversions tolerate rounding — a recipe survives a gram either way. But some do not: medication doses, shipping weight brackets, fabric and lumber purchases, and anything specified in a contract deserve the exact factors this converter applies rather than the "roughly two" folk arithmetic. The famous cautionary tale is the 1999 Mars orbiter lost to a pound-force/newton mix-up; your stakes are smaller, but the lesson scales down perfectly well.
Frequently Asked Questions
Why does my 1 TB drive show only 931 GB?
Two counting conventions: drive marketing uses decimal (1 TB = 10¹² bytes) while operating systems count binary (2⁴⁰). The converter offers both, clearly labeled, so the “missing” space is just arithmetic.
Which gallon does the converter use?
Both, as separate units: US gallon (3.785 L) and imperial gallon (4.546 L). They differ by 20 percent, so the dropdown names them explicitly rather than guessing your region.
Why is temperature conversion different from other units?
Celsius and Fahrenheit have different zero points, not just different step sizes, so conversion needs the formula °F = °C × 9/5 + 32 rather than a simple factor. The tool applies the exact formulas, Kelvin included.
How precise are the conversion factors?
They are the internationally defined values — and several (inch, pound, US gallon) are exact definitions against metric. Displayed results are rounded for readability; the copy button provides full precision.