Convert Temperature from degrees Rankine to degrees Fahrenheit (rankine to fahrenheit)

degree Rankine to degree Fahrenheit Conversion Formula

Example

Let's convert 5 degree Rankine (R) to degree Fahrenheit (F).

Using the formula:

Therefore, 5 degree Rankine (R) is equal to -454.67 degree Fahrenheit (F).

What Is the Rankine Temperature Scale (°R)?

The Rankine scale (°R) is a temperature measurement system built on absolute zero, much like the Kelvin scale. However, Rankine is specifically designed to work with the Fahrenheit system. Think of it as the Fahrenheit version of Kelvin, used primarily by engineers in the United States.

Why Is Rankine an Absolute Temperature Scale?

The Rankine scale is an absolute temperature scale, meaning its starting point—0 °R—is absolute zero. This is the coldest possible temperature in the universe, where all atomic and molecular motion stops completely.

Unlike scales such as Celsius and Fahrenheit, which have arbitrary zero points, absolute scales begin at true zero. This distinction is vital in science and engineering, particularly when a calculation requires dividing one temperature by another.

How to Convert Fahrenheit to Rankine

Since Fahrenheit and Rankine share the same degree size, a change of 1°F is equivalent to a shift in 1°R.

To convert Fahrenheit (°F) to Rankine (°R), add 459.67 to the Fahrenheit value.

Formula: °R = °F + 459.67

Example: Water freezes at 32 °F. To find this on the Rankine scale, you would calculate: 32 + 459.67 = 491.67 °R

Rankine is an Absolute Temperature Scale

The Rankine scale is an absolute temperature scale that is comparable to the Kelvin scale. Its zero point, 0 °R, represents absolute zero, which is the theoretical temperature where all molecular movement comes to a halt.

Unlike relative scales such as Fahrenheit or Celsius, which have arbitrary zero points (like the freezing point of water), Rankine starts from a true fundamental zero.

Where Is the Rankine Scale Used?

You will almost exclusively find the Rankine scale in engineering and thermodynamics fields within the United States.

Many scientific laws, especially those related to gases and energy efficiency (such as the Ideal Gas Law), require an absolute temperature to yield accurate results.

Rankine allows engineers working with imperial units (feet, pounds, Fahrenheit) to perform these critical calculations without first converting everything to Kelvin, which is the absolute scale for the metric system. It streamlines their workflow by keeping all units consistent.

Converting To and From Rankine

Rankine's arithmetic is deliberately simple, because it shares its degree size with Fahrenheit exactly as Kelvin shares its degree size with Celsius.

• °R = °F + 459.67
• °F = °R − 459.67
• °R = K × 1.8
• K = °R / 1.8

Two consequences follow. First, a difference of one degree Rankine and one degree Fahrenheit are the same interval, so any formula involving a temperature change can be carried between the scales untouched. Second, absolute zero is 0 °R = −459.67 °F, and water freezes at 491.67 °R.

By convention the scale is written without the degree sign in modern usage — 100 R, not 100 °R — matching the way Kelvin is written.

What is a degree Fahrenheit (°F)?

A degree Fahrenheit (°F) is the unit of temperature used in the imperial system of measurement.

Who Invented the Fahrenheit Scale?

The Fahrenheit scale was created in 1724 by the German physicist Daniel Gabriel Fahrenheit. He based his scale on three fixed points:

• The zero point (0 °F) was set by the temperature of a freezing mixture of brine (ice, water, and ammonium chloride).
• The second point (32 °F) was the freezing point of water, and the third (96 °F) was his best estimate of the average human body temperature.
• Later, the scale was tweaked so that the boiling point of water is exactly 212 °F—a full 180 degrees above freezing.

Where Is the Fahrenheit Scale Used Today?

While most of the world has adopted the Celsius scale for everyday temperature measurement, the Fahrenheit scale remains the official scale in the United States, its territories (like Puerto Rico and Guam), and a few other countries, including the Bahamas, Palau, and the Cayman Islands.

In the United Kingdom, both Fahrenheit and Celsius are used to describe temperature; Fahrenheit remains more familiar to older people and is often heard in casual conversation.

How to Convert Fahrenheit to Celsius (Formula)

You can easily convert any temperature from Fahrenheit to Celsius using a simple formula. To convert a temperature from Fahrenheit (F) to Celsius (C), subtract 32 from the Fahrenheit temperature and then multiply the result by 5/9.

The Fahrenheit to Celsius formula is: C = (F − 32) × 5/9

For example, to convert a pleasant day of 77 °F to Celsius: C = (77 − 32) × 5/9 = 45 × 5/9 = 25 °C

degree Rankine to degree Fahrenheit Conversion Table

Here are some quick reference conversions from degree Rankine (R) to degree Fahrenheit (F):