Intro
Polyconvert is a library of functions for converting between different units of measurement. It currently consists of 17 top level categories, each with several different units of measurement. The project currently supports JavaScript only but it would be nice to add more languages in the future!
If you find this tool useful you may also like this abbreviations gist and this formatting gist to help you turn your converted values into legible strings.
Contents
Install
Node
Package on npm: https://www.npmjs.com/package/@jgphilpott/polyconvert
Install with:
npm i @jgphilpott/polyconvertThen require it:
const polyconvert = require('@jgphilpott/polyconvert')Link
The other option you have is to link to the polyconvert.min.js file from an HTML document for use in the browser, like this:
<script src="polyconvert.min.js"></script>You can either link to the polyconvert.min.js file in this repo or download it and use your own copy.
Usage
The library features the polyconvert object that contains all of the formulas. The top level keys represent all the different categories available, see the object map below:
polyconvert = {
angle: {...},
area: {...},
data: {...},
density: {...},
dimension: {...},
energy: {...},
frequency: {...},
illumination: {...},
length: {...},
magnetomotive: {...},
mass: {...},
pressure: {...},
radiation: {...},
speed: {...},
temperature: {...},
time: {...},
volume: {...}
}The second level keys represent all the different units of measurement available within that category. See the object map below using the data category as an example:
polyconvert.data = {
bit: {...},
byte: {...},
kilobyte: {...},
megabyte: {...},
gigabyte: {...},
terabyte: {...},
petabyte: {...},
exabyte: {...},
zettabyte: {...},
yottabyte: {...}
}The third level keys represent all the different units of measurement that you can convert the original unit into and the values are formulas in the format of a function. See the object map below using the bit unit as an example:
polyconvert.data.bit = {
bit: f(x) = x,
byte: f(x) = x/8,
kilobyte: f(x) = x/8e+3,
megabyte: f(x) = x/8e+6,
gigabyte: f(x) = x/8e+9,
terabyte: f(x) = x/8e+12,
petabyte: f(x) = x/8e+15,
exabyte: f(x) = x/8e+18,
zettabyte: f(x) = x/8e+21,
yottabyte: f(x) = x/8e+24
}So, to use these functions, reference them through the polyconvert object and pass in the value you want to convert, like this:
polyconvert.data.bit.byte(100) // Returns 12.5 meaning that 100 bits equals 12.5 bytesTo reverse the conversion simply switch the order of the unit keys, like this:
polyconvert.data.byte.bit(12.5) // Returns 100 meaning that 12.5 bytes equals 100 bitsTesting
The Polyconvert library includes comprehensive testing to ensure accuracy and reliability. The test suite validates conversions using two complementary approaches:
Internal Consistency Tests
These tests verify that forward and reverse conversions return to the original value. For example:
- Convert 1 meter → feet → back to meters should equal 1 meter
- Convert 1 kilogram → pounds → back to kilograms should equal 1 kilogram
This ensures that conversion formulas are mathematically consistent and properly inverted.
External Validation Tests
These tests validate conversions against well-known values from reputable sources including:
- NIST (National Institute of Standards and Technology)
- International standards bodies (SI units, ISO standards)
- Widely accepted scientific references
Example validations:
- 1 meter = 3.28084 feet
- 0°C = 32°F (freezing point of water)
- 100°C = 212°F (boiling point of water)
- 1 kilogram = 2.20462 pounds
- 1 inch = 2.54 centimeters (exact)
- 1 atmosphere = 101325 pascals (exact)
The external validation tests cover all major categories including length, mass, temperature, volume, pressure, energy, data, time, speed, angle, area, and frequency conversions.
Running Tests
All tests can be run with the command:
npm testThis will execute both the internal consistency tests and external validation tests, providing comprehensive verification of all conversion formulas.
Contribute
There are two main ways you can contribute to the Polyconvert library.
1) Adding a new language, category or unit for conversion. 2) Report an inaccurate formula or typo.
See below for more information on each of the options, also feel free to simply ask any question you like.
Adding Features
Currently this library supports JavaScript only but it would be nice to add more languages in the future! It would also be nice to add new categories and units for conversion since the current list is not universal, yet. If you need an idea for a new category to work on I suggest browsing the UnitConverters.net website, this site can also be useful for testing the accuracy of existing formulas.
If you would like to contribute in this way please start by opening a feature request. Once your work is done and ready for review you can proceed to opening a pull request.
Reporting Errors
I have done my best to ensure the accuracy of all the formulas but I am only human and I can easily make mistakes! If you find an inaccurate formula or typo please don't hesitate to open a bug report.
The library includes comprehensive testing to ensure accuracy:
Internal Consistency Tests: Validate that forward and reverse conversions return to the original value (e.g., meter → foot → meter should equal the original meter value).
External Validation Tests: Validate conversions against well-known values from reputable sources like NIST (National Institute of Standards and Technology) and international standards bodies. These tests verify that conversions match widely accepted reference values (e.g., 1 meter = 3.28084 feet, 0°C = 32°F, 1 kg = 2.20462 pounds).
All tests can be run with the command npm test.
If you have any other issues with the Polyconvert library then please open a general issue. Your efforts will improve the functionality and usability of this tool for everyone, thanks in advance!
Categories
Each category below is available as a top level key in the polyconvert object. An object map of each category is available below.
Angle
The Angle category provides 6 different units for conversion, see the object map below:
polyconvert.angle = {
degree: {...},
gradian: {...},
milliradian: {...},
radian: {...},
arcSecond: {...},
arcMinute: {...}
}Area
The Area category provides 15 different units for conversion, see the object map below:
polyconvert.area = {
nanometerSq: {...},
micrometerSq: {...},
millimeterSq: {...},
centimeterSq: {...},
decimeterSq: {...},
meterSq: {...},
decameterSq: {...},
hectometerSq: {...},
kilometerSq: {...},
inchSq: {...},
footSq: {...},
yardSq: {...},
mileSq: {...},
acre: {...},
hectare: {...}
}Data
The Data category provides 10 different units for conversion, see the object map below:
polyconvert.data = {
bit: {...},
byte: {...},
kilobyte: {...},
megabyte: {...},
gigabyte: {...},
terabyte: {...},
petabyte: {...},
exabyte: {...},
zettabyte: {...},
yottabyte: {...}
}
Note: These data units use decimal (SI) prefixes (k=10^3, M=10^6, etc.). Binary IEC units (kibibyte KiB = 1024 bytes, mebibyte MiB, etc.) are not included. If you need binary units open a feature request.
Density
The Density category provides 8 different units for conversion, see the object map below:
polyconvert.density = {
gramCentimeterCu: {...},
gramMeterCu: {...},
kilogramCentimeterCu: {...},
kilogramMeterCu: {...},
ounceInchCu: {...},
ounceFootCu: {...},
poundInchCu: {...},
poundFootCu: {...}
}Dimension
The Dimension category provides 2 different units for conversion, see the object map below:
polyconvert.dimension = {
d2: {...},
d3: {...}
}Energy
The Energy category provides 11 different units for conversion, see the object map below:
polyconvert.energy = {
joule: {...},
kilojoule: {...},
wattHour: {...},
kilowattHour: {...},
electronvolt: {...},
calorie: {...},
kilocalorie: {...},
btu: {...},
footPound: {...},
// Power (time-dependent) units:
watt: {...},
kilowatt: {...}
}
Note: Listed quantities are energy units except watt and kilowatt which are power (rate). Converting between power and energy requires a duration (seconds) when calling those functions.
Frequency
The Frequency category provides 4 different units for conversion, see the object map below:
polyconvert.frequency = {
hertz: {...},
kilohertz: {...},
megahertz: {...},
gigahertz: {...}
}Illumination
The Illumination category provides 4 different units for conversion, see the object map below:
polyconvert.illumination = {
phot: {...},
lux: {...},
nox: {...},
flame: {...}
}Length
The Length category provides 13 different units for conversion, see the object map below:
polyconvert.length = {
nanometer: {...},
micrometer: {...},
millimeter: {...},
centimeter: {...},
decimeter: {...},
meter: {...},
decameter: {...},
hectometer: {...},
kilometer: {...},
inch: {...},
foot: {...},
yard: {...},
mile: {...}
}Magnetomotive
The Magnetomotive category provides 5 different units for conversion, see the object map below:
polyconvert.magnetomotive = {
milliampere: {...},
ampere: {...},
abampere: {...},
kiloampere: {...},
gilbert: {...}
}Mass
The Mass category provides 13 different units for conversion, see the object map below:
polyconvert.mass = {
nanogram: {...},
microgram: {...},
milligram: {...},
centigram: {...},
decigram: {...},
gram: {...},
decagram: {...},
hectogram: {...},
kilogram: {...},
ounce: {...},
pound: {...},
stone: {...},
ton: {...}
}Pressure
The Pressure category provides 5 different units for conversion, see the object map below:
polyconvert.pressure = {
bar: {...},
pascal: {...},
atmospheric: {...},
psi: {...},
torr: {...}
}Radiation
The Radiation category provides 14 different units for conversion, see the object map below:
polyconvert.radiation = {
nanogray: {...},
microgray: {...},
milligray: {...},
centigray: {...},
decigray: {...},
gray: {...},
decagray: {...},
hectogray: {...},
kilogray: {...},
megagray: {...},
gigagray: {...},
teragray: {...},
petagray: {...},
exagray: {...}
}Speed
The Speed category provides 25 different units for conversion, see the object map below:
polyconvert.speed = {
millimeterSecond: {...},
millimeterMinute: {...},
millimeterHour: {...},
centimeterSecond: {...},
centimeterMinute: {...},
centimeterHour: {...},
meterSecond: {...},
meterMinute: {...},
meterHour: {...},
kilometerSecond: {...},
kilometerMinute: {...},
kilometerHour: {...},
inchSecond: {...},
inchMinute: {...},
inchHour: {...},
footSecond: {...},
footMinute: {...},
footHour: {...},
yardSecond: {...},
yardMinute: {...},
yardHour: {...},
mileSecond: {...},
mileMinute: {...},
mileHour: {...},
knots: {...}
}
Note: Knots here means nautical miles per hour (1 knot = 1852 meters per hour).
Temperature
The Temperature category provides 3 different units for conversion, see the object map below:
polyconvert.temperature = {
celsius: {...},
fahrenheit: {...},
kelvin: {...}
}Time
The Time category provides 13 different units for conversion, see the object map below:
polyconvert.time = {
nanosecond: {...},
microsecond: {...},
millisecond: {...},
second: {...},
minute: {...},
hour: {...},
day: {...},
week: {...},
month: {...},
year: {...},
decade: {...},
century: {...},
millennium: {...}
}
Note: Month and year conversions use the Gregorian mean values (1 month = 30.436875 days, 1 year = 365.2425 days = 31,556,952 s). Longer spans (decade, century, millennium) are derived from these, improving precision over earlier rounded (365.25 / 30.417) approximations.
Volume
The Volume category provides 21 different units for conversion, see the object map below:
polyconvert.volume = {
nanometerCu: {...},
micrometerCu: {...},
millimeterCu: {...},
centimeterCu: {...},
decimeterCu: {...},
meterCu: {...},
decameterCu: {...},
hectometerCu: {...},
kilometerCu: {...},
inchCu: {...},
footCu: {...},
yardCu: {...},
mileCu: {...},
milliliter: {...},
liter: {...},
teaspoon: {...},
tablespoon: {...},
cup: {...},
pint: {...},
quart: {...},
gallon: {...}
}Polyconvert is developed and maintained by @jgphilpott.