Accurate unit conversions, verified by engineers.
Free, exact, well-sourced unit converters built and reviewed by engineering faculty. Every conversion factor verified against BIPM, NIST, and primary scientific standards. Live calculators, complete conversion tables, and worked examples for every pair.
Browse by category
Centimeter, meter, foot, inch, mile, nautical mile, micrometer, angstrom, parsec — 64 units across metric, imperial, astronomical, atomic, and typographic systems.
Open Length hubSquare meters, hectares, acres, square feet, bigha, guntha, cent, kanal, tsubo — 73 units across metric, imperial, US survey, Indian regional, and scientific systems.
Open Area hubLitres, gallons (US and Imperial), cubic meters, cubic feet — for cooking, fuel, shipping, and industrial process applications.
Open Volume hubKilograms, pounds, ounces, tonnes, grams, troy units — for shipping, cooking, jewellery, science, and engineering.
View statusCelsius, Fahrenheit, Kelvin, Rankine — with the exact offset formulas physics and engineering students need.
View statusSeconds, minutes, hours, days, weeks, years — including astronomical time, sidereal day, and legacy units.
View statusCurrency conversions, basis points, percentage calculators, and financial-ratio utilities for accounting and finance professionals.
View statusMost-used conversions
The most-searched length conversions globally — open instantly for the live calculator, the exact formula, a conversion table, and contextual examples.
Centimeter to Meter
1 cm = 0.01 m. The most-searched length conversion worldwide.
Meter to Feet
1 m = 3.28084 ft. Body height between metric and imperial countries.
Inch to Centimeter
1 in = 2.54 cm. TV diagonal sizes, paper, and US-localised products.
Kilometer to Mile
1 km = 0.621371 mi. Road distances, running events, and aviation routes.
Mile to Kilometer
1 mi = 1.60934 km. Marathon distances, road trips, and international travel.
Feet to Meter
1 ft = 0.3048 m. Aviation altitude, building heights, sports.
Why ExpertCalculator?
Engineering-reviewed, source-cited
Every conversion factor on this site is verified against authoritative sources: the BIPM SI Brochure, the NIST Guide to the SI, NIST SP 811, the 1959 International Yard and Pound Agreement, and others. Every converter page cites five distinct sources so you can independently verify the math.
Math precision built in
The site is a deterministic static-site generator. Every page is regenerated from spreadsheet data and validated by three automatic checks: structural integrity (placeholders, schema, headings), numerical precision (relative error < 1e-6 against canonical factors), and content depth (per-page-type word-count thresholds).
Authored by engineering faculty
Content is written by Sunith Babu L, Ph.D., Lead Engineer, and reviewed by Girish V Kulkarni Ph.D.. Both are engineering academics with formal credentials in measurement science.
What's a converter page actually like?
Each converter page includes:
- Live calculator — sticky right-rail calculator with instant conversion as you type
- The exact formula — multiplication factor sourced from primary standards
- Worked examples — 2-3 real-world scenarios specific to the unit pair (not generic body-height filler)
- Conversion table — 15 standard values pre-computed for quick reference
- FAQ — common questions answered concisely
- Unit definitions — what each unit is, where it came from, where it's used today
- Source citations — five authoritative references per page