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Unit Converter

Convert between 100+ units across 10 categories — instantly, for free.

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Common Length

  • 1 mile = 1.60934 km
  • 1 foot = 30.48 cm
  • 1 inch = 2.54 cm
  • 1 yard = 0.9144 m

Common Weight

  • 1 kg = 2.20462 lb
  • 1 lb = 453.592 g
  • 1 stone = 6.35 kg
  • 1 oz = 28.3495 g

Common Temperature

  • 0°C = 32°F
  • 100°C = 212°F
  • 37°C = 98.6°F
  • −40°C = −40°F

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The Most Complete Free Unit Converter Online

Texterfly's Unit Converter gives you instant, accurate conversions across 10 measurement categories and 100+ units — from everyday conversions like kilometers to miles or Celsius to Fahrenheit, to technical ones like pascals to PSI or kilowatt-hours to BTU. No ads in the way of your results, no account required.

Unlike most converters that show you one result at a time, this tool also offers an "All Conversions" table — enter a single value and instantly see it converted into every unit in the category at once. Perfect for engineering spec sheets, recipe scaling, or international trade documents.

How to Use the Unit Converter

  1. Pick a category — Length, Weight, Temperature, Area, Volume, Speed, Time, Digital Storage, Pressure, or Energy.
  2. Choose your From and To units from the dropdowns. Hit the ⇄ button to instantly swap them.
  3. Type your value. The result appears immediately — no submit button needed.
  4. See the formula used for the conversion, shown below the result.
  5. Expand "All conversions" to see your value in every unit of the category at once.
  6. Copy any result with one click. Recent conversions are saved in your session history.

Common Conversions & Quick Reference

Length Conversions

1 kilometer0.621371 miles
1 mile1.60934 km
1 meter3.28084 feet
1 foot0.3048 meters
1 inch2.54 centimeters
1 yard0.9144 meters

Weight Conversions

1 kilogram2.20462 pounds
1 pound0.453592 kg
1 ounce28.3495 grams
1 stone6.35029 kg
1 metric ton2204.62 pounds
1 US ton907.185 kg

Temperature Conversions

0°C32°F / 273.15 K
100°C212°F / 373.15 K
37°C (body)98.6°F
20°C (room)68°F
−40°C−40°F
0 K (abs. zero)−273.15°C

Volume Conversions

1 liter0.264172 US gallons
1 US gallon3.78541 liters
1 cup (US)236.588 ml
1 pint (US)473.176 ml
1 fluid oz29.5735 ml
1 cubic meter1000 liters

Frequently Asked Questions

How do I convert kilometers to miles?

Select "Length", set From to "Kilometer" and To to "Mile", enter your value. Multiply km × 0.621371. Example: 10 km = 6.214 miles.

How do I convert Celsius to Fahrenheit?

Select "Temperature", choose Celsius → Fahrenheit. Formula: °F = (°C × 9/5) + 32. Example: 100°C = 212°F.

How do I convert kg to lbs?

Select "Weight", choose Kilogram → Pound. Formula: lbs = kg × 2.20462. Example: 70 kg = 154.324 lbs.

Can I see all unit conversions at once?

Yes! After entering a value, click "Show all conversions" below the result to see a table of your value converted into every unit in the selected category.

How accurate are the conversions?

Results are shown to up to 8 significant digits using exact or widely accepted conversion factors from NIST and ISO standards.

Does this work on mobile?

Yes, the converter is fully responsive and works on any device or screen size.

What Measurement Categories Are Supported?

  • Length — mm, cm, m, km, in, ft, yd, mi, nmi, light year
  • Weight / Mass — µg, mg, g, kg, metric ton, oz, lb, stone, US ton, carat
  • Temperature — Celsius, Fahrenheit, Kelvin, Rankine
  • Area — mm², cm², m², km², in², ft², yd², mi², acre, hectare
  • Volume — ml, L, m³, tsp, tbsp, fl oz, cup, pint, quart, gallon (US & UK)
  • Speed — m/s, km/h, mph, knot, ft/s, Mach, speed of light
  • Time — ns, µs, ms, s, min, h, day, week, month, year, decade
  • Digital Storage — bit, byte, KB, MB, GB, TB, PB (with kilobit/megabit)
  • Pressure — Pa, kPa, MPa, bar, mbar, PSI, atm, Torr, mmHg
  • Energy — J, kJ, cal, kcal, Wh, kWh, eV, BTU, ft·lbf, therm

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