Unit Converter — Metric, Imperial & 14 Types

Quick Start Guide

  1. Select category: Choose from 14 categories including Length, Weight, Time, Volume, Power, and Force.
  2. Enter value: Type the number you want to convert.
  3. Choose units: Select From and To units from the dropdowns.
  4. View conversion: See converted value calculated automatically.
  5. Swap units: Press S key or click swap button to reverse conversion.

Understanding Unit Conversion

How conversions actually work

Every unit in a category converts through a common base unit — meters for length, watts for power, newtons for force. Converting 10 miles to kilometers really means: convert miles to meters, then meters to kilometers. This is why adding a new unit only requires one conversion factor, not one factor per possible pair.

US customary vs Imperial (UK) units

A US gallon and a UK (Imperial) gallon are not the same size — a UK gallon is about 20% larger. The same is true for pints and fluid ounces. Volume units here are labeled (US) or (UK) so you convert against the right standard instead of assuming they match.

Data storage vs network speed

File sizes (KB, MB, GB) are measured in bytes and typically use binary multiples of 1024. Network and internet speeds (Kbps, Mbps, Gbps) are measured in bits and use decimal multiples of 1000 — and a byte is 8 bits. That is why a "100 Mbps" connection tops out around 12.5 MB per second, not 100.

Features

14 Categories: Comprehensive support for length, weight, time, volume, power, force, speed, data, and more.

Multi-Unit View: See all conversions for a category at a glance.

Smart History: Remembers recently used unit pairs for quick access.

Export: Export conversion results to JSON, CSV, or PDF.

Common Use Cases

Cooking: cups to milliliters, ounces to grams, Fahrenheit to Celsius.

Travel: miles to kilometers, pounds to kilograms, gallons to liters.

Construction: inches to centimeters, square feet to meters, quarts to liters.

Science: metric and Imperial conversions, temperature scales (K/C/F), energy units (J/cal/kWh).

Frequently Asked Questions

Multiply inches by 2.54. For example, 12 inches = 30.48 cm. You can also select Length in this converter, enter your value in inches, and select cm as the output unit for instant results.
Multiply pounds by 0.453592. For example, 150 lbs = 68.04 kg. Use the Weight category and select lbs to kg for an instant conversion.
We use high-precision conversion factors. Results are typically accurate to 10+ decimal places, which is sufficient for almost all scientific and engineering needs.
The converter supports 14 categories: length, weight, temperature, area, volume, speed, data, pressure, energy, frequency, angle, time, power, and force. Pick a category, then expand the Popular Pairs section for one-click common conversions.
A US gallon (3.785 liters) and a UK/Imperial gallon (4.546 liters) are different sizes — the UK gallon is about 20% larger. The same applies to pints and fluid ounces. Volume units are labeled (US) or (UK) so you convert against the correct standard.
Network speeds (Kbps, Mbps, Gbps) measure bits per second using decimal multiples of 1000, while file sizes (KB, MB, GB) measure bytes using binary multiples of 1024, and a byte is 8 bits. A "100 Mbps" connection downloads at roughly 12.5 MB per second, not 100 — use the Data category to convert between bit-based and byte-based units directly.
Yes! Enter a value and the Multi-Unit View in the help panel shows all possible conversions in that category. Click any unit to set it as your target. This is especially useful for comparing different units quickly.
Click the swap button between the From and To units, or press the 'S' key on your keyboard. This instantly reverses the conversion direction, useful when you want to see the reverse calculation.
Yes! The calculator remembers your recently used unit pairs for each category. When you select a category, recent unit pairs appear at the top of the unit dropdowns for quick access to your frequently used conversions.
Yes. In guest mode you can export your calculations to JSON. Signing in adds PDF and CSV export. Click the export button to download your results — useful for record-keeping, sharing, or importing into other tools.
Yes. Your calculation history is saved automatically. As a guest you can keep up to 50 calculations per workspace on your device. Sign in for free to keep up to 100 per workspace and access them from any device.
Yes. The Unit Converter is free to use with no sign-up required. A free account adds more calculation history, multiple workspaces, and access to your saved data from any device.

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