All Unit Converter: one place for the conversions you actually look up
Most people don't need a converter with 300 obscure units. They need the same handful of answers, fast: how many centimetres are in an inch, what 350°F is in Celsius for the oven, how many megabytes are really in a "1 GB" file. This site collects the nine tools I found myself reaching for most often and puts them in one fast, no-login, works-offline page. Everything runs in your browser — nothing you type is sent to a server or stored.
Quick reference: the 20 conversions people search for most
You can often skip the calculator entirely. These are the exact, standards-based values — the same constants the tools on this site use. Bookmark this table; most day-to-day questions are answered right here.
| If you have | It equals | Good to know |
|---|---|---|
| 1 inch | 2.54 cm (exactly) | Defined by international agreement, not rounded |
| 1 foot | 0.3048 m (exactly) | = 12 inches = 30.48 cm |
| 1 mile | 1.609344 km | A nautical mile is longer: 1.852 km |
| 1 kilogram | 2.2046226 lb | A rough "×2.2" is close enough for most uses |
| 1 pound (lb) | 453.592 g | = 16 ounces; 1 oz = 28.35 g |
| 0°C | 32°F | Water freezes |
| 100°C | 212°F | Water boils at sea level |
| 37°C | 98.6°F | Normal human body temperature |
| 180°C (fan oven) | 356°F | Common baking temperature |
| 1 hour | 3,600 seconds | 1 day = 86,400 s |
| 1 GB (binary, GiB) | 1,024 MB | Why a "500 GB" drive shows as ~465 GB in your OS |
| 1 GB (decimal, marketing) | 1,000 MB | How manufacturers count storage |
| Decimal 255 | FF (hex) = 11111111 (binary) | The largest value in one byte |
Not sure which tool you need? Match your task below
Each row links to the tool built for that job:
- Following a recipe from another country → use Mass (grams ↔ ounces) and Temperature (Celsius ↔ Fahrenheit).
- DIY, carpentry or buying furniture abroad → Length handles inches, feet, centimetres and metres.
- Checking a download size or data plan → Data covers bits, bytes, and the binary-vs-decimal gigabyte trap explained above.
- A programming or computer-science assignment → Number System for binary/octal/hex, and Power Mod for modular exponentiation used in cryptography.
- Working out a sale price → Discount shows the final price and exactly how much you save.
- Payroll, timesheets or project timelines → Time converts between seconds, minutes, hours and days.
- Formatting a bio or social-media post → Text restyles plain text and gives live character counts.
What makes this converter different
- It works offline. This is a Progressive Web App — once loaded, it keeps working with no connection, so it's reliable on a patchy mobile signal or in an exam hall.
- Nothing is tracked or stored. Every calculation happens on your device in JavaScript. There is no account, no upload, and no server round-trip — see the Privacy Policy for specifics.
- The constants are honest. Where a conversion is defined exactly (like 1 inch = 2.54 cm), the tool uses the exact value rather than a rounded shortcut.
Frequently asked questions
Why does my new 500 GB drive only show about 465 GB?
Because two different "gigabytes" are in play. Drive makers advertise using decimal gigabytes (1 GB = 1,000,000,000 bytes), while Windows reports in binary gibibytes (1 GiB = 1,073,741,824 bytes) but still labels them "GB." Same physical space, different counting. The Data converter lets you switch between both.
Is a quick "multiply by 2" close enough for kg to pounds?
For a rough idea, yes — but the real factor is 2.2046, so multiplying by 2 undercounts by about 10%. On a 30 kg suitcase that's a 6 lb error, which matters at an airport weight limit. Use the Mass converter when the number counts.
Do I need to install anything or create an account?
No. The site works instantly in any modern browser with no sign-up. On a phone you can optionally tap "Add to Home Screen" to use it like an app, but that's entirely optional.
Who built this
All Unit Converter is built and maintained by Arun Neupane, a Computer Science (CSIT) student and web developer from Parbat, Nepal. I built it because I was tired of ad-heavy converter sites that reload the page for every calculation and bury the answer under pop-ups. If a conversion here is ever wrong or a unit is missing, the contact page reaches me directly — corrections are genuinely welcome. You can read more on the About page.