Unit Converter Online (100% Free & Private)
Free unit converter that runs in your browser. No sign-up, no install.
Universal Metric & Imperial Unit Converter
What this tool does and who it is for
Pick a category, choose the unit you have and the unit you want, type a value, and the converter returns the result with the conversion factor shown. Categories include length, weight, area, volume, speed, temperature and digital storage, with US and metric units side by side.
It covers the conversions Americans run into constantly: miles and kilometers, pounds and kilograms, feet and meters, gallons and liters, Fahrenheit and Celsius. A swap button flips the direction without retyping.
One detail to watch: digital storage uses binary multiples, so 1 KB is 1,024 bytes here. Drive makers often label capacity using powers of 1,000, so numbers may differ from the box.
Official Formula / Technical Standard
Real-World Worked Scenario
Entering baseline parameters produces an instant, real-time mathematical breakdown with side-by-side comparative totals.
When people use it
Following a recipe from another country
Convert cups, fluid ounces and milliliters, or Fahrenheit to Celsius for oven temperatures.
Checking a distance or speed
Turn kilometers per hour into miles per hour for a trip, or miles into kilometers for a race.
Sizing a space
Convert square feet to square meters or acres to hectares when reading a floor plan or a land listing.
Understanding file sizes
Compare megabytes, gigabytes and terabytes when buying storage or checking upload limits.
Notes for US users
- Gallons, quarts, pints, cups and fluid ounces here are US customary units, which differ from imperial units used in the UK.
- The US still uses Fahrenheit for weather and cooking, while most science and the rest of the world use Celsius. The temperature mode handles both and Kelvin.
- Tons in this tool means metric tons, not US short tons of 2,000 pounds. Convert through pounds if you need short tons.
- For legal trade measurements, such as fuel or scales, NIST's Office of Weights and Measures sets the standards.
Limits and what to double-check
- •Some area and speed factors are rounded to a few significant digits, so very precise engineering work should use exact published values.
- •Fuel economy, pressure, energy and time are not included, and there are no custom units.
- •Digital units use 1,024-based steps rather than 1,000, which may differ from how storage is marketed.
Expert Best Practices & Common Pitfalls
Recommended Best Practices
- •Verify input values against your latest financial statements or tax documents.
- •Model best-case, average-case, and conservative scenarios to understand financial variability.
- •Review long-term interest costs and compounding schedules before committing to large loans.
Common Mistakes to Avoid
- •Using outdated tax rates or interest assumptions from previous calendar years.
- •Forgetting secondary expenses like closing fees, maintenance, or local taxes.
- •Relying on rough estimates rather than calculating exact monthly amortizations.
Features & Security Architecture
- 100% Client-Side: Zero server uploads ensure complete privacy and data confidentiality
- Fast Results: Processing happens on your own device, so there is no upload or server queue to wait for
- No Sign-Up Required: Completely free to use with no daily usage caps or account requirements
- Works on All Devices: Fully responsive across desktop, tablet, and mobile browsers
Frequently Asked Questions
How does the Unit Converter work?▼
The Unit Converter runs 100% inside your web browser using modern client-side JavaScript. It performs calculations, conversions, and document processing locally on your device without sending any data to external servers.
Is this unit converter completely free to use?▼
Yes. This tool is completely free with no usage limits, no subscriptions, and no registration required.
Is my data private when using the Unit Converter?▼
Yes. Because all operations execute locally on your computer or phone, your inputs, documents, and data never leave your browser.
How do I convert Fahrenheit to Celsius by hand?▼
Subtract 32 from the Fahrenheit value, then multiply by five-ninths. For example, 68 degrees F minus 32 is 36, times 5/9 is 20 degrees C. The tool does this when you choose the temperature category and set the units.
Are US gallons the same as UK gallons?▼
No. A US gallon is about 3.785 liters, while an imperial gallon is about 4.546 liters. This tool uses US gallons, quarts, pints and cups. If a recipe or a car spec is from the UK, check which gallon it means.
Why does my 1 TB drive show less space?▼
Manufacturers label capacity with 1 TB meaning one trillion bytes, but many operating systems report in binary units where a gigabyte is 1,073,741,824 bytes. The difference makes the drive appear smaller. Formatting overhead takes a bit more.
What is the difference between a ton and a metric ton?▼
In the US, a short ton is 2,000 pounds, while a metric ton is 1,000 kilograms, about 2,204.6 pounds. The tool's ton option is the metric one. If you need short tons, convert the weight to pounds and divide by 2,000.