Free Unit Converter Online
Convert between units in real time. Pick a category, enter a value, and see the result instantly.
From
Please enter a valid number
To
3.28
feet (ft)
Usage Examples
Click any example to load it into the converter
Length
↗
1 meter to feet
1 m = 3.28 ft
Length
↗
1 mile in feet to meters
5280 ft = 1609.34 m
Weight
↗
1 kilogram to pounds
1 kg = 2.20 lb
Weight
↗
150 pounds to kilograms
150 lb = 68.04 kg
Volume
↗
1 US gallon to liters
1 gal = 3.79 L
Speed
↗
100 km/h to mph
100 km/h = 62.14 mph
Key Features
Multiple Categories
Length, weight, volume, and speed — all in one tool.
Bidirectional
Convert both ways. Swap units with one click using the direction button.
Precision Control
Adjust decimal places (0–4) for the exact rounding you need.
Instant Results
Conversion updates in real time as you type — no buttons needed.
Frequently Asked Questions
General
What is the Unit Converter?
The Unit Converter provides real-time bidirectional conversion across four measurement categories: length (meter, kilometer, mile, foot, inch, yard), weight (kilogram, gram, pound, ounce), volume (liter, milliliter, US gallon, US quart, US cup), and speed (m/s, km/h, mph, knots). Select a category tab, enter a value in any unit on the left, choose a target unit on the right, and the converted result appears instantly.
How to Use This Tool
- Select a category tab: Length, Weight, Volume, or Speed. The unit dropdowns update with the relevant choices.
- Enter a value in the "From" field and select source and target units. The result updates in real time.
- Adjust decimal precision (0-4 places) with the dropdown. Use Swap (⇄) to reverse direction, or click any example card to load a preset conversion.
Example
Input:
1 meter → feet
Output:
3.28 feet
Details
What is the difference between US gallons and UK (imperial) gallons?
This unit converter uses US liquid gallons. 1 US gallon = 3.785411784 liters, while 1 UK imperial gallon = 4.54609 liters, a difference of about 20%. This distinction matters significantly when interpreting fuel economy figures or following recipes between US and UK sources.
How precise are the conversion factors?
All conversion factors are defined by international agreement (the International Yard and Pound agreement of 1959) and are exact. This unit converter computes conversions directly from the source unit to the target unit without intermediate rounding, using the full precision of JavaScript's 64-bit floating-point numbers (about 15-16 significant digits).
What units should I use for GPS coordinates and navigation?
GPS and navigation primarily use metric units: meters for distance, kilometers per hour or meters per second for speed. Nautical and aviation contexts use nautical miles (1 NM = 1852 meters exactly) and knots (nautical miles per hour). This unit converter includes knots in the Speed category for aviation and maritime use.
Why does the tool not include data storage units?
Data storage units involve binary prefixes (kibibytes, mebibytes) vs. decimal prefixes (kilobytes, megabytes) that have caused decades of confusion. Because this ambiguity requires the user to specify which system they are using, data unit conversion is beyond the scope of this general unit converter.
How do I convert compound units like fuel efficiency?
Compound unit conversions require multi-step calculations that cannot be handled by a simple unit converter. For mpg to L/100km: first convert miles to kilometers, then convert gallons to liters, then compute L/100km = (liters / km) × 100. Break the conversion into separate steps, convert each component with this tool, and combine the results manually.