Free online unit converter supporting real-time two-way metric and imperial conversion across length, weight, temperature, area, volume and speed. Calculated locally in your browser, no upload, completely free, no sign-up.
Convert metric and imperial units in real time right in your browser, no install and no upload needed. Pick a category, enter a value, and the conversion between the two units updates instantly. All calculations run locally, nothing is uploaded.
How to use
1
Choose a category
Click a tab at the top to pick length, weight, temperature, area, volume or speed
2
Enter a value and pick units
Type a number in either field and select the source and target units
3
See the two-way result
The other field updates automatically; tap the middle button to swap units
FAQ
Is my data uploaded?
No. All conversions are calculated locally in your browser via JavaScript. Nothing is sent to a server, and everything is cleared when you close the page.
Which unit categories are supported?
Six common categories: length (meter, foot, mile, etc.), weight (kilogram, pound, ounce, etc.), temperature (Celsius, Fahrenheit, Kelvin), area (square meter, square foot, acre, etc.), volume (liter, gallon, cubic meter, etc.) and speed (km/h, mph, m/s, etc.).
How accurate are the conversions?
All conversion factors use international standard values (e.g. 1 inch = 2.54 cm, 1 pound = 0.45359237 kg). Results keep an appropriate number of significant digits for everyday and engineering use.
What are the temperature conversion formulas?
Celsius to Fahrenheit: F = C x 9/5 + 32; Fahrenheit to Celsius: C = (F - 32) x 5/9; Kelvin to Celsius: K = C + 273.15. The tool handles the non-linear temperature conversion automatically.
Why are there two gallon options?
Gallons come in US gallons (gal, about 3.785 liters) and imperial gallons. This tool uses US gallons by default, the most common international standard. For reference, 1 imperial gallon is about 4.546 liters.
Is the tool free? Do I need to register?
Completely free, no registration or login required, unlimited use. All categories and units are fully open and available anytime.