Our mission
We believe unit conversion should be simple, instant, and free. Whether you're a student doing homework, an engineer designing parts, a scientist running experiments, a cook scaling a recipe, or a traveler estimating distances — you shouldn't have to fight with a clunky tool or pay for an app just to convert a value. UnitSwiftPro is built to be the most useful, fastest, and cleanest unit converter on the web.
What we offer
Instant results
Type a value, see the conversion. No button clicks, no page reloads, no waiting.
Standard factors
Every conversion uses internationally recognized factors from NIST, BIPM, and ISO 80000.
Formulas shown
See the exact math behind every conversion. Great for students and engineers.
Quick tables
Reference tables for the most common values in every category.
Works anywhere
Responsive design that works perfectly on phone, tablet, and desktop. No install needed.
Works offline
Once the page loads, all conversion logic runs locally in your browser. No internet required.
Private
No tracking, no sign-up, no account required. Your conversions stay on your device.
100% free
No subscription, no premium tier, no usage limits. Free forever.
Categories & coverage
UnitSwiftPro covers 15 main measurement categories with 326+ individual units and 473 dedicated converter pages:
- Length & distance — meters, feet, inches, miles, kilometers, nautical miles, light-years, and more
- Weight & Mass — kilograms, pounds, ounces, grams, tons, stones, carats, and more
- Temperature — Celsius, Fahrenheit, Kelvin, Rankine, Réaumur
- Area — square meters, acres, hectares, square feet, square miles
- Volume — liters, gallons, cups, cubic meters, fluid ounces, tablespoons
- Speed — mph, kph, m/s, knots, mach, speed of light
- Pressure — pascals, bar, psi, atmospheres, torr, mmHg
- Energy — joules, calories, kilowatt-hours, BTU, electronvolts
- Power — watts, kilowatts, horsepower, BTU/h
- Time — seconds, minutes, hours, days, weeks, years, decades
- Data Storage — bytes, kilobytes, megabytes, gigabytes, terabytes, and binary IEC units
- Force — newtons, pound-force, kilogram-force, dynes
- Angle — degrees, radians, gradians, arcminutes, arcseconds
- Frequency — hertz, kilohertz, megahertz, gigahertz, RPM
- Fuel Economy — MPG (US & UK), km/L, L/100km
Supported measurement systems
- International System of Units (SI / metric) — the global standard since 1960
- Imperial system (UK) — pounds, feet, UK gallons, stones
- US customary units — US gallons, US tons, fluid ounces
- Natural & scientific units — Planck, Bohr radius, electron mass, light-year, parsec, astronomical unit
- Historical units — Roman, biblical, ancient Greek, Egyptian cubits, Russian arshin
How we ensure accuracy
Every conversion factor used in UnitSwiftPro is sourced from authoritative references:
- NIST (National Institute of Standards and Technology) — the U.S. reference for physical constants
- BIPM (Bureau International des Poids et Mesures) — the international reference for SI units
- ISO 80000 — international standard for quantities and units
- Specialized references for niche units (typography, screen sizes, historical units)
Important disclaimer
For mission-critical applications — medical dosing, legal measurements, aerospace, large-scale engineering, financial calculations — always independently verify with the original source. UnitSwiftPro is intended for everyday conversions and educational use.
Technology
UnitSwiftPro is built with modern web standards: pure HTML, CSS, and JavaScript with no frameworks. The site is served by Cloudflare's global edge network, which means it loads fast from anywhere in the world. All conversion logic runs in your browser, so the site works even when you're offline.
Ownership & contact
UnitSwiftPro (unitswiftpro.com) is independently owned and operated. We are reachable via our contact page, and we read every message. Suggestions, bug reports, and partnership inquiries are all welcome.
Editorial standards
We don't publish content we wouldn't link to ourselves. Every page on UnitSwiftPro is reviewed for accuracy and clarity. We don't use AI-generated filler. Conversion factors are double-checked against at least two authoritative sources. When we make a mistake, we fix it and document the correction.
Privacy & data
UnitSwiftPro does not collect, store, or sell any personal data. We don't require an account. We don't set tracking cookies. All conversion input stays in your browser and is never sent to a server. Read our full Privacy Policy.
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