What does this tool do?
Unit Converter Pro is an advanced tool that converts a wide range of units at once across length, weight, volume, area, speed, pressure, and energy. It covers specialist units like light years, nanometers, BTU, electronvolts, and Mach, making it ideal for engineers, science students, and technical users.
How to use it
- Enter your values into the fields.
- The result is calculated instantly.
- Read or copy the result.
What sets it apart: scientific and technical units
This Pro edition goes beyond the basic converter. It includes units stretching from nanometers and light years in length, to stone in weight, to Mach in speed. It also adds two categories the simple tool lacks: pressure (pascals, bar, PSI, atmospheres, mmHg) and energy (joules, calories, kWh, BTU, electronvolts). Enter one value and every unit in that category is computed instantly in a single list, so you can compare them all at a glance.
Smart formatting for very small and very large numbers
When you work with extreme values like electronvolts or light years, results automatically switch to scientific notation (for example 1.602e-19) to stay readable. Otherwise numbers are shown with thousands separators and up to eight significant figures. The source unit is highlighted in the list, and a copy button beside each row lets you grab any result with one click. All calculations run in your browser and nothing is uploaded.
Frequently asked questions
What is the difference between Unit Converter Pro and the standard Unit Converter?
Pro adds pressure and energy categories plus scientific units such as light years, nanometers, stone, Mach, BTU, and electronvolts. The standard tool instead includes temperature and data categories. The standard version covers most everyday conversions, while Pro is broader for technical work.
Which reference values are used for the pressure and energy units?
Pressure uses the pascal as its base (1 bar = 100,000 Pa, 1 PSI ≈ 6894.76 Pa, 1 atm = 101,325 Pa). Energy uses the joule as its base (1 kcal = 4184 J, 1 kWh = 3.6 million J, 1 BTU ≈ 1055 J). Every conversion is built on these standard references.
Why are very small numbers shown like 1.602e-19?
For extremely small values such as electronvolts, when the result is below 1e-10 the tool automatically switches to scientific notation. This keeps the output compact and readable instead of printing a long string of zeros.
Is Unit Converter Pro free?
Yes. Unit Converter Pro and all 300+ tools on MagmaNex are completely free with no signup or account required.
Is my data safe?
Yes. Everything runs locally in your browser. The data you enter is never sent to a server, stored, or shared.
Does it work on mobile?
Yes. Unit Converter Pro works on phones, tablets and desktops — no app download needed.
🔒 Privacy: everything runs in your browser, your data is never sent to a server.