Local Calculation · Real-Time · Browser-Based
All-in-One Unit Converter
Convert units across 17 measurement categories — length, weight, temperature, volume, area, speed, energy, pressure, time, and more. Live conversion as you type, formula display, and browser-based processing.
unit-converter v2.0
Length Converter
Convert any unit in four steps
No signup, no install, no account. The tool remembers your last category and input.
Pick a category
Length, weight, temperature, volume — choose from 17 measurement types in the sidebar.
Select units
Choose source and target units from the dropdowns. Swap them with one click.
Enter value
Type any number — decimals, negatives, or scientific notation. The result updates live.
Copy or share
Grab the result, download it as a text file, or share via WhatsApp.
Precision, predictability, and processing
What this converter does with your values — and how calculations are executed.
Local in-browser logic
All calculations use IEEE 754 double-precision floating-point arithmetic directly inside your browser. No conversion inputs are transmitted to remote servers.
Scientific notation
Very small results (below 1e-6) or very large ones (above 1e9) automatically switch to scientific notation. All other values show up to 6 decimal places without trailing zeros.
Standard definitions
Conversion factors use standard unit definitions and published reference values. Dedicated formulas handle non-linear conversions (such as temperature scales and fuel economy).
17 measurement categories
Click any card to jump to that category in the workspace.
Popular conversion pairs
Real-world examples across everyday use cases.
Length
Weight
Temperature
Area
Volume
Speed
What it does, and what it does not
Clear boundaries so you know when to use this tool and when to reach for another.
What it does
- Convert 200+ units across 17 measurement categories.
- Live conversion as you type — no submit button needed.
- Dedicated calculations for reciprocal fuel and temperature formulas.
- Swap units with one click to reverse direction.
- Formula display for every conversion.
- Copy, download, or share results instantly.
- Scientific notation for extreme values.
- Full dark mode with system preference detection.
What it does not
- Convert currency (use the Currency Converter tool).
- Replace specialized engineering software for mission-critical calculations.
- Sync settings across devices — data stays in one browser only.
- Handle unit systems outside the 17 supported categories.
Common issues and fixes
Quick answers to the most frequent problems.
Result shows 0 or blank
Make sure you've entered a valid number in the "Value" field. The tool accepts integers, decimals, and scientific notation (e.g. 1e5).
Temperature or Fuel seems wrong
Temperature and reciprocal fuel economy units (like L/100km) use dedicated non-linear formulas rather than simple multiplication factors.
Result is in scientific notation
This is intentional. Values below 1e-6 or above 1e9 automatically use scientific notation for readability.
Formula doesn't match my textbook
Some units have multiple regional conventions (such as US vs Imperial gallons). This tool applies standardized reference constants.
Frequently asked questions
Honest answers about the Unit Converter.
What units can I convert with this tool?
This converter supports 17 categories: length, weight, temperature, volume, area, speed, energy, pressure, time, data storage, force, power, fuel consumption, electric current, voltage, density, and angle.
How do I convert kilometres to miles?
Select the Length category, choose Kilometres as input and Miles as output, then enter your value. 1 kilometre equals approximately 0.621371 miles.
How do I convert Celsius to Fahrenheit?
Select the Temperature category, choose Celsius as input and Fahrenheit as output, and enter your value. The formula used is (°C × 9/5) + 32.
How accurate are the conversions?
All conversions use internationally recognized standard conversion factors and IEEE 754 double-precision arithmetic. Dedicated non-linear logic is applied for reciprocal units like fuel consumption and temperature scales.
Is my data sent to a server?
No conversion values are transmitted to our servers; calculations execute locally in your browser. If you voluntarily use the WhatsApp share button, the generated text snippet is handed off to WhatsApp.
Can I convert multiple units at once?
The tool converts from one unit to another at a time. Use the swap button to quickly reverse direction.