SciPy - Unit Conversion Constants

---

---

In SciPy the Unit Conversion constants are provided in the scipy.constants module which enables easy conversion between different units of measurement. This module includes constants for converting lengths, masses, times, temperatures and more.

For example scipy.constants.inch converts inches to meters, scipy.constants.minute converts minutes to seconds and scipy.constants.atm converts standard atmosphere pressure to pascals.

These constants facilitate precise scientific calculations by ensuring consistency across different units in physics, engineering and other disciplines. By using these predefined constants we can perform conversions with high accuracy and reduced error.

The scipy.constants module provides different types of unit conversion constants which can be used to convert between different units of measurement. Following are the some key types of unit conversion constants that are available in Scipy −

Length Conversion Constants

The Length Conversion Constants are used to convert between different units of length with ease. These constants represent the conversion factors between meters and other units such as inches, feet, miles etc.

To convert one unit into another unit we have multiply the number of units with appropriate conversion constant. Here are the key length conversion constants available in scipy −

Inch to Meter (inch)

Generally 1 inch is equal to 0.0254 meters. The inch method of scipy.constants is used to convert a length measured in inches to meters. Here, is the example which shows how to convert inches into meters with the help of scipy.constants.inch method −

from scipy.constants import inch
inches = 10
meters = inches * inch
print(f"{inches} inches is equal to {meters} meters")

Following is the output of converting 10 inches to meters −

10 inches is equal to 0.254 meters

Foot to Meter (foot)

Generally 1 foot is equal to 0.3048 meters. The foot method in scipy.constants allows us to convert a length in feet to meters. Following is the example which converts 10 feets into meters with the help of scipy.constants.foot method −

from scipy.constants import foot
feet = 10
meters = feet * foot
print(f"{feet} feet is equal to {meters} meters")

Following is the output of converting 10 feets to meters −

10 feet is equal to 3.0479999999999996 meters

Yard to Meter (yard)

Normally 1 yard is equal to 0.9144 meters. In Scipy we have the method yard in scipy.constants module which is used for converting yards to meters. Below is the example which is converting 10 yards into meters using scipy.constants.yard −

from scipy.constants import yard
yards = 10
meters = yards * yard
print(f"{yards} yards is equal to {meters} meters")

Following is the output of converting 10 yards to meters −

10 yards is equal to 9.143999999999998 meters

Astronomical Unit to Meter (astronomical_unit or au)

Generally we can say 1 light year is equal to approximately 9.46 trillion kilometers or about 9.46 x 10^15meters. The method astronomical_unit of scipy.constants is used to express distances between stars and galaxies in scipy. Here is the example which converts 1 light year into meters using scipy.constants.astronomical_unit−

from scipy.constants import light_year
ly = 1
meters = ly * light_year
print(f"{ly} light year is equal to {meters} meters")

Following is the output of converting 10 yards to meters −

1 light year is equal to 9460730472580800.0 meters

List of Unit Conversion Constants

In this section we have discussed only few length conversion constants. There are other constants also such as Light Year to Meter (light_year), Parsec to Meter (parsec) and etc.

Mass Conversion Constants

In SciPy Mass conversion constants are provided in the scipy.constants module which allows for easy conversion between different units of mass whether we are dealing with everyday units like pounds and grams or specialized units like atomic mass units and carats.

These constants represent the conversion factors between kilograms i.e. the SI base unit of mass and other units like grams, pounds and atomic mass units. These constants are particularly useful in scientific computations where precise unit conversions are required.

To convert a mass from one unit to another we have to multiply the amount of mass by the corresponding conversion constant. For example to convert 10 pounds to kilograms we have to multiply 10 by the value of pound i.e. 0.45359237

Following are the key mass conversion constants available in scipy.constants module. Let's see them in detail with an example −

Gram to Kilogram (gram)

In general, 1 gram is equal to 0.001 kilograms. The gram method of scipy.constants module is used to convert a mass measured in grams to kilograms. Following is the example of converting 1000 grams into kilograms with the help of scipy.constants.gram method −

from scipy.constants import gram
grams = 1000
kilograms = grams * gram
print(f"{grams} grams is equal to {kilograms} kilograms")

Below is the output of converting 1000 grams to kilograms −

1000 grams is equal to 1.0 kilograms

Metric Ton to Kilogram (metric_ton)

Generally 1 metric ton is given as to 1000 kilograms. The metric_ton method of scipy.constants module is used to convert metric tons to kilograms. Here is the example which converts 10 tons into metric tons using the scipy.constants.metric_ton method −

from scipy.constants import metric_ton
tons = 10
kilograms = tons * metric_ton
print(f"{tons} metric ton is equal to {kilograms} kilograms")

Below is the output of converting 1000 grams to kilograms −

10 metric ton is equal to 10000.0 kilograms

Here we have discussed about a few mass conversion constants there are many more such as Pound to Kilogram (pound), Ounce to Kilogram (ounce), Atomic Mass Unit to Kilogram (atomic_mass), Carat to Kilogram (carat), Grain to Kilogram (grain) and etc.

Time Conversion Constants

SciPy provides a set of time conversion constants within the scipy.constants module. These constants allow for easy conversion between various units of time such as seconds, minutes, hours, days and years.

Each constant represents the number of seconds in the corresponding unit of time by making it straightforward to convert between different time units.

To convert from one unit of time to anothe we should multiply the number of units by the appropriate conversion constant. For example when we want to convert 2 hours to seconds we would multiply 2 by the value of hour i.e. 3600.0.

There are different types of Time conversion constants available in Scipy. Let's the key Time conversion constants in detail with an example −

Second (second)

The second is the base unit of time in the International System of Units (SI). It is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom.

This precise definition ensures uniformity and accuracy in time measurement by making it a fundamental constant in various scientific and engineering applications.

To convert from one unit of time to another we have to multiply the number of units by the appropriate conversion constant. For example if we want to convert 2 hours to seconds we have to multiply 2 by the value of hour i.e. 3600.0.

Here in this example we are using the method hour available in scipy.constants module.−

from scipy.constants import hour

# Convert 1 hour to seconds
seconds_in_an_hour = hour
print(f"1 hour is equal to {seconds_in_an_hour} seconds.")

Below is the output of converting 1 hour grams to seconds −

1 hour is equal to 3600.0 seconds.

Day (day)

In SciPy library, the day constant in the scipy.constants module represents the number of seconds in one day. This is useful for converting between time units or performing time-related calculations. We have the method day in scipy.constants module to convert the day data into seconds.

Following is the example which converts a day into seconds with the help of scipy.constants.day−

from scipy.constants import day
days = 1
seconds = days * day
print(f"{days} day is equal to {seconds} seconds")

Following is the output, which converted a day into seconds format −

1 day is equal to 86400.0 seconds

Note:

In Time conversion constants we have some other time conversions such as minute, week, year, julian year etc.

Temperature Conversion Constants

In SciPy temperature conversion constants are provided through the scipy.constants module. These constants are used to convert between different temperature scales such as Celsius, Fahrenheit and Kelvin etc. Below is the detailed look at the temperature conversion constants available in SciPy −

To convert one unit into another unit we have multiply the number of units with appropriate conversion constant. Here are the key length conversion constants available in scipy −

Zero Celsius in Kelvin (zero_Celsius)

This constant represents the difference between the Celsius and Kelvin temperature scales. The Kelvin scale starts at absolute zero so to convert a temperature in Celsius to Kelvin we have to add 273.15. Following is the mathematical formula of converting celsius to kelvin −

K=C+273.15

Below is the mathematical formula of converting kelvin to celsius −

C=K-273.15

Following is the example which converts the Celsius temperature to Kelvin with the help of scipy.constants.zero_celsius method −

from scipy.constants import zero_Celsius

celsius_temp = 25  # Temperature in Celsius
kelvin_temp = celsius_temp + zero_Celsius
print(f"{celsius_temp} C is equal to {kelvin_temp} K")

Following is the output of converting 25 celsius to kelvin temperature −

25 C is equal to 298.15 K

Degree Fahrenheit to Celsius (degree_Fahrenheit)

This constant represents the factor to convert a change in temperature from Fahrenheit to Celsius. To convert Fahrenheit to Celsius we have to subtract 32 from the Fahrenheit value and then multiply by this factor.−

Here is the example which converts the Fahrenheit temperature to Celsius with the help of scipy.constants.degree_Fahrenheit method −

from scipy.constants import degree_Fahrenheit

fahrenheit_temp = 77  # Temperature in Fahrenheit
celsius_temp = (fahrenheit_temp - 32) * degree_Fahrenheit
print(f"{fahrenheit_temp} F is equal to {celsius_temp} C")

Below is the output of converting 77 Fahrenheit to Celsius temperature −

77 F is equal to 25.0 C

Energy Conversion Constants

The Energy Conversion Constants in SciPy provide a straightforward way to convert energy values between various units which is crucial in fields like physics, chemistry and engineering. These constants allow for precise and reliable conversions by making them essential tools in scientific and engineering computations.

By using these constants we can easily switch between units like joules, calories, electron volts and more by ensuring that our calculations are accurate and consistent across different energy scales. Whether dealing with thermodynamic calculations, electrical energy or quantum mechanics, these conversion constants are indispensable for handling energy-related data.

Following are the key Energy Conversion Constants which are provided by scipy.constants module in Scipy −

Electron Volt to Joules (eV)

The Electron Volt to Joules(eV) constant represents the energy equivalent of one electron volt in joules. The electron volt (eV) is a unit of energy commonly used in atomic and particle physics where it represents the energy gained by an electron and when it is accelerated through an electric potential difference of one volt.

The value of 1 electron volt is equal to 1.602176634e-19 J. In Scipy scipy.constants module provides a method eV which is used to convert Electron Volt to Joules.

Following is the example of converting the Electron Volt to Joules with the help of scipy.constants.eV method available in Scipy −

from scipy.constants import eV

energy_eV = 1  # Energy in electron volts
energy_J = energy_eV * eV
print(f"{energy_eV} eV is equal to {energy_J} J")

Following is the output of using the eV method of scipy.constants module −

1 eV is equal to 1.602176634e-19 J

Calorie to Joules (calorie)

The Calorie to Joules (calorie) constant represents the energy equivalent of one calorie in joules. The calorie is a unit of energy commonly used in nutrition to quantify the amount of energy provided by food.

1 Calorie is equal to 4.184 J. The scipy.constants module in Scipy provides a method namely, calorie which converts Calorie to Joules.

Here is the example which converts 1 calorie to Joules using the method scipy.constants.calorie −

from scipy.constants import calorie

energy_cal = 1  # Energy in calories
energy_J = energy_cal * calorie
print(f"{energy_cal} cal is equal to {energy_J} J")

Here is the output of converting the calorie into Joules −

1 cal is equal to 4.184 J

Note

We have discussed about a few Energy conversion constants available in scipy.constants but still there are few more such as British Thermal Unit to Joules (Btu), Hartree Energy to Joules (Hartree), Kilowatt-hour to Joules (kWh) etc.

Pressure Conversion Constants

The Pressure Conversion Constants in SciPy simplify unit conversions in scientific computations by ensuring precision and uniformity across disciplines like physics, chemistry and engineering.

By providing standardized values for various pressure units the SciPy allows researchers and engineers to easily convert between units such as pascals, atmospheres and torrs by facilitating accurate calculations and data analysis in a wide range of scientific applications.

To convert pressure values between different units we have to multiply by the appropriate conversion constant. For example when we want to convert 1 atmosphere to pascals then we need to multiply by the atmosphere constant.

Below are the key pressure conversion constants available in SciPy −

Atmosphere (atmosphere)

The Atmosphereconstant represents the pressure of one standard atmosphere which is defined as 101,325 pascals. It is often used as a reference in various scientific fields. In scipy.constants module we have the method atmosphere.

Following is the example which shows how to use the scipy.constants.atmosphere method for converting atmospheres to pascals −

from scipy.constants import atmosphere

pressure_pa = 2 * atmosphere  # Example: 2 atmospheres in pascals
print(f"2 atmospheres is equal to {pressure_pa} Pa")

Following is the output of converting the atmosphere into pascals −

2 atmospheres is equal to 202650.0 Pa

Bar (bar)

The Bar is another unit of pressure which is defined as 100,000 pascals. It is commonly used in meteorology and engineering.

In this example we are showing how to use the scipy.constants.bar method for converting bar to pascals −

from scipy.constants import bar

pressure_pa = 1.5 * bar  # Example: 1.5 bar in pascals
print(f"1.5 bar is equal to {pressure_pa} Pa")

Following is the output of converting the bar into pascals −

1.5 bar is equal to 150000.0 Pa

Note:

In this section we have discussed only few Pressure Conversion Constants, but there are other constants available in scipy such as Torr (torr), mmHg (Millimeter of Mercury) (mmHg), psi (Pound per Square Inch) (psi) etc.

Power Conversion Constants

In SciPy Power Conversion Constants are part of the scipy.constants module. These constants are used to convert between different units of power such as watts, horsepower and other related units. Below are the key power conversion constants available in SciPy −

Horsepower (hp)

Generally one horsepower is equal to approximately 745.7 watts. This unit is commonly used to measure the power of engines, especially in automobiles. We have the method horsepower in scipy.constants to convert the power into horsepower.

Following is the example which uses the scipy.constants.horsepower to convert the power into horsepower −

from scipy.constants import horsepower

power_hp = 1  # Power in horsepower
power_watt = power_hp * horsepower
print(f"{power_hp} hp is equal to {power_watt} watts")

1 hp is equal to 745.6998715822701 watts

Erg per Second (erg/s)

Generally one horsepower is equal to approximately 745.7 watts. This unit is commonly used to measure the power of engines, especially in automobiles. We have the method horsepower in scipy.constants to convert the power into horsepower.

Following is the example which uses the scipy.constants.horsepower to convert the power into horsepower −

from scipy.constants import erg
print(f"1 Erg per second is equal to {erg} Watts")

Below is the output of converting erg per second to watts −

1 Erg per second is equal to 1e-07 Watts

There are few other conversion constants available in power conversion Constants such as British Thermal Unit per Hour (BTU/h) etc.

Volume Conversion Constants

In SciPy, Volume Conversion Constants are available through the scipy.constants module by providing tools to convert between various units of volume. These constants are crucial for scientific calculations involving different volume measurements.

Below are the key crucial conversion constants available in scipy.constants module −

Liter (litre)

A liter is a common unit of volume, especially in chemistry and everyday measurements. In SI units 1 liter is defined as 0.001 cubic meters. In Scipy we have a method litre in scipy.constants module which converts cubic meters to liters. Below is the example of using the scipy.constants.litre method −

from scipy.constants import litre

cubic_meters = 2  # Volume in cubic meters
liters = cubic_meters / litre
print(f"{cubic_meters} cubic meters is equal to {liters} liters")

Below is the output of converting cubic meters to liters −

2 cubic meters is equal to 2000.0 liters

Gallon (gallon)

The gallon is commonly used in the United States to measure liquid volumes. In SI units, 1 gallon is approximately 0.00378541 cubic meters. The scipy.constants has a method namely, gallon which converts cubic meters to Gallons. Here is the example of working with the method scipy.constants.gallon −

from scipy.constants import gallon

cubic_meters = 0.01  # Volume in cubic meters
gallons = cubic_meters / gallon
print(f"{cubic_meters} cubic meters is equal to {gallons} gallons")

Below is the output of converting cubic meters to gallons −

0.01 cubic meters is equal to 2.6417205235814842 gallons

Note: In Volume Conversions constants we have many more constants such as Cubic Inch (inch), Cubic Foot (foot) etc, only fe discussed in this section.