How accurate are the conversions?

All conversion factors are sourced from NIST and international measurement standards. Results are precise to 6+ significant digits.

Why does my 1 TB hard drive show less space?

Manufacturers define 1 TB as 1 trillion bytes (decimal), but operating systems use binary where 1 TiB = 1,099,511,627,776 bytes. This ~7% difference means a 1 TB drive shows about 931 GB.

Is my data private when using UnitSnap?

Yes. Every converter runs 100% in your browser. No data is sent to any server.

Do I need to install anything?

No. All converters run directly in your web browser. No installation, no downloads, no extensions required.

Free Online Unit Converters That Just Work

Q: What's the difference between US and UK gallons?

A US gallon is 3.785 liters while a UK Imperial gallon is 4.546 liters — about 20% larger. This also affects fuel efficiency measurements.

15 fast, free, and private unit conversion tools. Every converter runs 100% in your browser — no data is ever sent to a server. No sign-up required.

15 converters & counting

📏 Measurement

📏

Length Converter

Convert between meters, feet, inches, kilometers, miles, yards, and more.

⚖️

Weight Converter

Convert between kilograms, pounds, ounces, grams, stones, and tons.

📐

Area Converter

Convert between square meters, square feet, acres, hectares, and more.

🧪

Volume Converter

Convert between liters, gallons, milliliters, cups, fluid ounces, and more.

🌡 Science & Engineering

🌡

Temperature Converter

Convert between Celsius, Fahrenheit, and Kelvin instantly.

💨

Speed Converter

Convert between km/h, mph, m/s, knots, and Mach number.

⛽

Fuel Efficiency Converter

Convert between km/L, miles per gallon (US/UK), and L/100km.

🔵

Pressure Converter

Convert between Pascal, Bar, ATM, PSI, mmHg, and inHg.

⚡

Energy Converter

Convert between Joules, kWh, Calories, BTU, and Electronvolts.

🔌

Power Converter

Convert between Watts, Kilowatts, Horsepower, BTU/h, and more.

💻 Digital & Everyday

💾

Data Storage Converter

Convert between bytes, KB, MB, GB, TB, and PB (binary & decimal).

🥄

Cooking Units Converter

Convert between cups, tablespoons, teaspoons, milliliters, and grams.

🌐

Time Zone Converter

Convert time between world time zones — IST, EST, PST, GMT, UTC, and more.

⏱️

Time Duration Converter

Convert between seconds, minutes, hours, days, weeks, months, and years.

📍

Angle Converter

Convert between degrees, radians, gradians, turns, and arcminutes.

📚 Guides & Resources

Understand the systems behind the numbers. Our in-depth guides explain the history, science, and practical tips behind unit conversion.

Metric vs Imperial: The Complete Guide — History, key differences, and quick conversion tricks
Cooking Measurements Guide — US cups vs metric cups, tablespoon sizes, and recipe conversion tips
Data Storage Units Explained — Binary vs decimal, and why your drive shows less space
Temperature Scales Guide — Celsius, Fahrenheit, and Kelvin: history, formulas, and reference points
Fuel Efficiency Explained — MPG, km/L, L/100km and tips to improve your mileage
World Time Zones & DST Guide — How time zones work, DST explained, and scheduling tips
Pressure Units Explained — From Pascal to PSI: how pressure is measured and converted
Energy & Power Units Guide — Joules, kWh, Calories, BTU, and understanding your electricity bill
Understanding Angles — Degrees, radians, and gradians: the maths behind rotation

View all guides →

Why Use UnitSnap?

UnitSnap provides fast, accurate unit conversions with zero distractions. Unlike other converters cluttered with ads and pop-ups, UnitSnap is clean, lightweight, and built for speed.

100% Private

Every conversion happens in your browser. No data is sent to any server. Your inputs never leave your device.

Instant Results

Results update as you type — no need to click a "convert" button. See all common conversions at a glance with our quick reference tables.

Works Everywhere

UnitSnap works on desktop, tablet, and mobile. No app to install, no account to create. Just open and convert.

Accurate & Reliable

All conversion factors are sourced from NIST (National Institute of Standards and Technology) and international measurement standards. Results are precise to 6+ significant digits.

The Story of Units: Why We Convert

The need for unit conversion stems from one of humanity's longest-running coordination problems: different regions adopted different measurement systems over thousands of years, and we still live with the consequences.

Metric vs Imperial: The World's Measurement Divide

Today, only three countries — the United States, Myanmar, and Liberia — have not officially adopted the metric system. The rest of the world uses the International System of Units (SI), standardized in 1960 by the General Conference on Weights and Measures. This means:

A recipe from France uses grams and Celsius, while an American recipe uses cups and Fahrenheit — the Cooking Converter bridges this gap
Speed limits in Canada are in km/h, while the US uses mph — convert instantly with the Speed Converter
Real estate in India is measured in square feet, while Europe uses square meters — the Area Converter handles both

Temperature: Three Scales, Three Origins

The three temperature scales each have fascinating origins:

Fahrenheit (°F) — Proposed by Daniel Fahrenheit in 1724. He set 0F as the temperature of an ice-salt-water mixture and 96F as roughly human body temperature. Water freezes at 32F and boils at 212F.
Celsius (°C) — Devised by Anders Celsius in 1742 (originally inverted). Water freezes at 0C and boils at 100C, making it intuitive for everyday use and scientific work.
Kelvin (K) — The SI unit for thermodynamic temperature. Starts at absolute zero (0 K = −273.15C), the theoretical lowest possible temperature where molecular motion ceases.

Convert between all three instantly with the Temperature Converter.

Digital Storage: Why Your 1 TB Drive Shows 931 GB

One of the most confusing unit conversions involves data storage. Hard drive manufacturers use decimal (SI) prefixes where 1 TB = 1,000,000,000,000 bytes, but operating systems use binary prefixes where 1 TiB = 1,099,511,627,776 bytes. The result: your "1 TB" drive shows only about 931 GB in Windows. The Data Storage Converter converts between both systems and shows the exact byte counts.

Quick Conversion Reference

1 mile = 1.609 km | 1 km = 0.621 miles
1 pound = 0.454 kg | 1 kg = 2.205 pounds
1 gallon (US) = 3.785 liters | 1 liter = 0.264 gallons
1 acre = 4,047 m² = 0.405 hectares
°F to °C: Subtract 32, multiply by 5/9
°C to °F: Multiply by 9/5, add 32

Frequently Asked Questions

UnitSnap includes 15 free converters: Length, Weight, Area, Volume, Temperature, Speed, Fuel Efficiency, Pressure, Energy, Power, Data Storage, Cooking Units, Time Zone, Time Duration, and Angle. All run directly in your browser with instant results.

Yes. Every converter runs 100% in your browser using client-side JavaScript. No data is sent to any server. Your inputs and conversion results never leave your device.

All conversion factors are sourced from NIST (National Institute of Standards and Technology) and international measurement standards. Results are precise to 6+ significant digits, suitable for engineering, scientific, and everyday use.

Hard drive manufacturers define 1 TB as 1 trillion bytes (decimal), but operating systems measure in binary where 1 TiB = 1,099,511,627,776 bytes. This ~7% difference means a "1 TB" drive shows about 931 GB in your OS. The Data Storage Converter shows both decimal and binary values.

A US gallon is 3.785 liters while a UK (Imperial) gallon is 4.546 liters — about 20% larger. This also affects fuel efficiency: a car getting 30 MPG (US) would show about 36 MPG using Imperial gallons. The Fuel Efficiency Converter handles both standards.

No. All converters run directly in your web browser — Chrome, Firefox, Safari, or Edge. No installation, no downloads, no extensions. Works on desktop, tablet, and mobile.