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Unit converter
Convert common and technical units with exact definitions, useful precision controls, and no account required.
Quick length conversion
Enter a value and choose units. Results update instantly.
1 in = 2.54 cm
All Length units
From 1 in| Unit | Value |
|---|---|
| Meter m | 0.0254 |
| Kilometer km | 0.0000254 |
| Centimeter cm | 2.54 |
| Millimeter mm | 25.4 |
| Micrometer μm | 25,400 |
| Nanometer nm | 25,399,999.9999999963 |
| Inch in | 1 |
| Foot ft | 0.0833333333 |
| Yard yd | 0.0277777778 |
| Mile mi | 0.0000157828 |
| Nautical mile nmi | 0.0000137149 |
| Light-year ly | 2.6847821184e-18 |
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Converters
Everyday measurements
Length
Convert metric, imperial, nautical, and astronomical length units.
Weight and Mass
Convert kilograms, pounds, ounces, stones, tons, and other mass units.
Temperature
Convert Celsius, Fahrenheit, Kelvin, and Rankine temperatures.
Area
Convert square metric and imperial units, acres, and hectares.
Volume
Convert liters, gallons, cups, and cubic metric or imperial units.
Speed
Convert kilometers per hour, miles per hour, knots, and other speed units.
Time
Convert seconds, minutes, hours, days, weeks, and fixed calendar approximations.
Pressure
Convert pascals, bar, atmospheres, psi, torr, and mercury column units.
Energy
Convert joules, calories, watt-hours, BTU, foot-pounds, and electronvolts.
Converters
Digital and typography
Data Storage
Convert bits, bytes, decimal storage units, and IEC binary units.
Data Transfer Rate
Convert bits and bytes per second across network and file transfer units.
Typography and Screen Length
Convert pixels at 96 PPI, points, picas, inches, and metric print lengths.
Metric Prefixes
Convert SI-prefixed values from nano and micro through giga and tera.
Digital Image Resolution
Convert digital image resolution units including dots and pixels per inch, centimeter, and meter.
Converters
Science and engineering
Force
Convert newtons, pound-force, kilogram-force, dynes, and related force units.
Frequency
Convert hertz and decimal frequency multiples from millihertz to terahertz.
Frequency and Wavelength
Convert electromagnetic frequency to vacuum wavelength and back.
Density
Convert mass density units used in science, engineering, and materials.
Acceleration
Convert acceleration units including standard gravity, gal, and feet per second squared.
Torque
Convert newton-meters, pound-feet, pound-inches, and kilogram-force meters.
Volume Flow Rate
Convert cubic meters, liters, gallons, and cubic feet per unit time.
Mass Flow Rate
Convert kilograms, grams, pounds, and metric tons per unit time.
Angular Acceleration
Convert angular acceleration units including radians, revolutions, degrees, and turns per second squared.
Converters
Electrical
Electric Current
Convert amperes and decimal current units from nanoamperes to kiloamperes.
Electric Resistance
Convert ohms, milliohms, kiloohms, megaohms, and other resistance units.
Electric Potential
Convert volts and SI-prefixed electric potential units.
Capacitance
Convert farads, millifarads, microfarads, nanofarads, and picofarads.
Inductance
Convert henries, millihenries, microhenries, nanohenries, and picohenries.
Electric Charge
Convert coulombs, ampere-hours, milliampere-hours, and elementary charges.
Electric Conductance
Convert siemens and SI-prefixed electrical conductance units.
Electric Conductivity
Convert electrical conductivity units including siemens per meter and related metric scales.
Electric Field Strength
Convert electric field strength units including volts per meter and newtons per coulomb.
Converters
Radiation
Beyond units
Calculators, files, and practical tools
Percentage Calculator
Solve the most common percentage questions with one calculator and see the equation used for each result.
Loan Calculator
Model principal, interest rate, and term with a month-by-month balance schedule.
Time Zone Converter
Choose real city-based time zones and convert a specific local time using the offset in effect on that date.
Easy Grader
Create a printable teacher grading table with decimal precision and configurable letter-grade thresholds.
PDF Merger
Select several PDFs, confirm page counts and order, then create one merged document locally.
Word Counter
Measure document length and reading time while identifying the most frequent meaningful words.
QR Code Generator
Preview and download a crisp PNG QR code generated entirely in the browser.
CSV to JSON Converter
Transform pasted table data into arrays of objects without sending the file to a server.
Image Background Remover
Remove white or other uniform backgrounds locally with a transparent PNG preview.
Recipe Scaler
Resize every ingredient together and display practical reduced fractions for kitchen use.
Electricity Cost Calculator
Translate a device power rating into practical kilowatt-hours and estimated utility cost.
Sunrise and Sunset Calculator
Get coordinate-based solar times with polar-day and polar-night detection.
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Popular city and standard-time routes
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Definitions before decimals
ConvertWin calculates through documented reference units and identifies assumptions such as 96 PPI pixels, vacuum wavelength, standard gravity, or US versus Imperial gallons.
Exact definitions stay exact internally. Rounding changes only the displayed result, and each converter links to its primary standards source.
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