Free Online Unit Converter
Instantly convert length, weight, temperature, area, volume, speed, time, data, pressure and energy. Accurate, private and free — everything runs in your browser.
All Units at a Glance
| Unit | Value | Symbol |
|---|
What is a Unit Converter?
A unit converter turns a measurement from one unit into another — pounds to kilograms, inches to centimeters, Fahrenheit to Celsius, miles to kilometers, square feet to square meters and many more. UnitsConverter.top covers ten everyday categories with 78 units, from US customary and imperial units to metric (SI) units, so cross-border shoppers, travelers, students, cooks and DIY builders get the number they need in one step.
Every calculation happens locally in your browser using internationally defined conversion factors — for example 1 inch is exactly 25.4 millimeters and 1 pound is exactly 0.45359237 kilograms. Nothing you type is uploaded, stored on a server, or shared with anyone. The tool is completely free, needs no account, and works on phones, tablets and desktops alike.
How to Use This Unit Converter
- Pick a category — length, weight, temperature, area, volume, speed, time, data, pressure or energy.
- Type a value in either box. The other side updates instantly, in both directions.
- Choose units from the dropdowns, or tap a common-conversion chip such as lb → kg or °F → °C.
- Use the swap button to flip the direction, and set decimal precision if you need an exact figure.
- Check the full table below to see your value in every unit of the category — click any row to make it the target.
Why Choose UnitsConverter.top
Bidirectional & Instant
Type in either field and the other updates live. No convert button, no page reload — results on every keystroke.
Exact Conversion Factors
Built on internationally defined constants (1 in = 25.4 mm exactly), with precision control up to 10 decimal places.
US ↔ Metric Focus
Quick chips for the conversions Americans actually need: lb to kg, in to cm, °F to °C, mi to km, gal to L, sqft to sqm.
Full-Category Table
See your value expressed in every unit of the category at once — perfect for comparing scales quickly.
Private by Design
All math runs on your device. No uploads, no accounts, no tracking of your numbers. History stays in your browser only.
Free & Unlimited
No paywall, no sign-up, no daily limits. Convert as much as you want, whenever you want, on any device.
Frequently Asked Questions
How do I convert pounds to kilograms?
Select the Weight category, type your value next to pounds (lb), and read the result in kilograms instantly. The exact factor is 1 lb = 0.45359237 kg. You can also tap the “lb → kg” quick chip to set both units in one click.
How do I convert Fahrenheit to Celsius?
Open the Temperature category, enter the Fahrenheit value and the Celsius result appears immediately. The formula used is °C = (°F − 32) × 5/9, so 68 °F equals exactly 20 °C. Kelvin is available too.
Is this unit converter free to use?
Yes. UnitsConverter.top is completely free with no sign-up and no limits. All calculations run inside your browser — your numbers are never uploaded to any server.
How accurate are the conversions?
Conversions use internationally defined exact factors where they exist (for example 1 inch = 25.4 mm exactly, 1 pound = 0.45359237 kg exactly) and standard scientific definitions elsewhere. You can display results with up to 10 decimal places.
Does the converter work on mobile phones?
Yes. The layout is fully responsive: the converter stacks vertically on small screens, the swap button rotates, and all controls are touch-friendly. No app install is needed — just open the page in your phone's browser.