One Converter for Length, Weight, Temperature, Pressure, Data Storage, and Seven More Categories
How many times have you Googled “psi to bar” or “cups to ml” this year? Every one of those searches is a small interruption. And if you’re doing engineering calculations, cooking from a recipe that uses US measurements, or trying to explain to a European colleague what 72 degrees Fahrenheit feels like — you’re doing these conversions constantly.
Unit Converter Pro covers 12 categories and over 100 units in a single tool. Pick a category, enter a value, and see every unit in that category converted simultaneously. No dropdown menus for the target unit — you see them all at once and copy whichever you need.
The 12 Categories
- Length: mm, cm, m, km, inches, feet, yards, miles, nautical miles, micrometers, nanometers, light years
- Weight: mg, g, kg, oz, lb, tons, stones, US tons, carats, micrograms
- Temperature: Celsius, Fahrenheit, Kelvin, Rankine (using exact formulas, not simple multiplication)
- Area: mm2, cm2, m2, km2, in2, ft2, acres, hectares
- Volume: ml, liters, US gallons, Imperial gallons, quarts, pints, cups, tablespoons, teaspoons, fluid ounces, cubic meters and feet
- Speed: m/s, km/h, mph, knots, ft/s, Mach
- Pressure: Pa, kPa, bar, psi, atm, mmHg, inHg
- Energy: J, kJ, cal, kcal, Wh, kWh, BTU, eV
- Time: milliseconds, seconds, minutes, hours, days, weeks, months, years
- Data: bits, bytes, KB, MB, GB, TB, KiB, MiB, GiB (both base-10 and base-2)
- Angle: degrees, radians, gradians, turns, arc minutes, arc seconds
- Frequency: Hz, kHz, MHz, GHz, RPM
How It Works
- Select a category tab
- Enter a value and choose the source unit
- Every other unit in that category updates instantly
- Click Copy on any result
Enter 1 GB in the Data category and you’ll immediately see 1,024 MB, 1,048,576 KB, 8,589,934,592 bits, and 0.931 GiB. No clicking through dropdowns to find the unit you need.
Who Needs This
- Engineers converting between pressure units (psi, bar, atm) or energy units (kWh, BTU, joules) for technical calculations
- IT people who deal with the GB vs. GiB confusion daily — this tool shows both standards side by side
- Anyone following a recipe that uses cups and tablespoons when your measuring tools show milliliters
- Travelers converting between miles and kilometers, Fahrenheit and Celsius, gallons and liters
- Students doing physics or engineering homework who need to verify their unit conversion math
A Note on Temperature
Temperature conversion isn’t a simple multiplication factor like most other unit conversions. The relationship between Celsius and Fahrenheit involves an offset (32 degrees), not just a ratio. This tool uses the exact conversion formulas, so 0 degrees C correctly shows as 32 degrees F, and the Kelvin conversions are equally precise.
Data Storage: GB vs. GiB
This trips people up constantly. A gigabyte (GB) is 1,000,000,000 bytes (base 10). A gibibyte (GiB) is 1,073,741,824 bytes (base 2). Your hard drive manufacturer uses GB. Your operating system often reports in GiB. This is why a “500 GB” drive shows up as ~465 GiB in your file manager. The Data category shows both standards so you can finally make sense of the discrepancy.
The Currency Converter Pro handles 36+ world currencies. The Time Zone Converter covers 35+ zones. The Number System Converter handles binary, octal, decimal, and hex.
Quick FAQ
Does anything get sent to a server?
No. All math runs in your browser. Your values stay on your device.
How accurate are the conversions?
They use standard conversion factors and exact formulas (especially for temperature). Accurate enough for engineering calculations, scientific work, and everyday use.
Free?
Completely. No accounts, no restrictions, no premium features locked behind a paywall.