Instantly Convert °F to °R or Rankine to Fahrenheit — Both Directions
Convert Fahrenheit to Rankine (°F → °R) or Rankine to Fahrenheit (°R → °F) instantly. Get the exact conversion with formula breakdown, reference table, and related temperature conversions — all free, no sign-up needed.
Fahrenheit and Rankine share the same degree size — making their conversion uniquely simple among temperature scales. Our converter handles both directions instantly using the exact offset of 459.67, with no rounding or approximation.
The Fahrenheit scale (°F) is a temperature scale proposed by Daniel Gabriel Fahrenheit in 1724. It sets the freezing point of water at 32°F and the boiling point at 212°F at standard atmospheric pressure — a range of 180 degrees. It is the primary temperature scale used in the United States for everyday measurements.
The Rankine scale (°R) is an absolute temperature scale proposed by Scottish engineer William John Macquorn Rankine in 1859. Like Kelvin, it starts at absolute zero — the coldest theoretically possible temperature — but uses Fahrenheit-sized degrees instead of Celsius-sized degrees. Absolute zero on the Rankine scale is 0°R = −459.67°F.
Because Fahrenheit and Rankine use identical degree sizes, converting between them requires only a single addition or subtraction. The exact offset is 459.67 — the absolute value of absolute zero in Fahrenheit. So: °R = °F + 459.67 and °F = °R − 459.67. No multiplication is needed — only a constant shift.
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The Fahrenheit to Rankine conversion is one of the simplest in all of temperature science. Since both scales use the same degree size, only a constant offset is needed. That offset — 459.67 — is the magnitude of absolute zero expressed in Fahrenheit (−459.67°F).
The figure below shows key reference temperatures side by side on both scales. Notice that every Rankine value is simply the Fahrenheit value plus 459.67 — the two scales are perfectly parallel with a constant shift.
The table below covers a wide range of Fahrenheit values converted to Rankine. All values use the exact formula °R = °F + 459.67. Celsius and Kelvin equivalents are also shown for full temperature context.
| Fahrenheit (°F) | Rankine (°R) | Celsius (°C) | Kelvin (K) | Reference Point |
|---|---|---|---|---|
| −459.67°F | 0°R | −273.15°C | 0 K | Absolute zero |
| −40°F | 419.67°R | −40°C | 233.15 K | °F = °C crossover point |
| 0°F | 459.67°R | −17.78°C | 255.37 K | Fahrenheit zero |
| 32°F | 491.67°R | 0°C | 273.15 K | Water freezing point |
| 50°F | 509.67°R | 10°C | 283.15 K | Cool spring morning |
| 68°F | 527.67°R | 20°C | 293.15 K | Standard room temperature |
| 72°F | 531.67°R | 22.22°C | 295.37 K | Comfortable indoor temp |
| 98.6°F | 558.27°R | 37°C | 310.15 K | Normal human body temp |
| 100°F | 559.67°R | 37.78°C | 310.93 K | Very hot summer day |
| 212°F | 671.67°R | 100°C | 373.15 K | Water boiling point |
| 451°F | 910.67°R | 232.78°C | 505.93 K | Paper ignition point |
| 500°F | 959.67°R | 260°C | 533.15 K | Oven baking temperature |
| 1000°F | 1459.67°R | 537.78°C | 810.93 K | Industrial furnace range |
| 2000°F | 2459.67°R | 1093.33°C | 1366.48 K | Steel melting range |
| 5778°F | 6237.67°R | 3203.33°C | 3476.48 K | Surface of the Sun (approx) |
The table below shows common Rankine values converted back to Fahrenheit using the formula °F = °R − 459.67. This is useful in engineering contexts where Rankine is the working unit and a Fahrenheit reference is needed.
| Rankine (°R) | Fahrenheit (°F) | Celsius (°C) | Kelvin (K) |
|---|---|---|---|
| 0°R | −459.67°F | −273.15°C | 0 K |
| 100°R | −359.67°F | −217.59°C | 55.56 K |
| 300°R | −159.67°F | −106.48°C | 166.67 K |
| 459.67°R | 0°F | −17.78°C | 255.37 K |
| 491.67°R | 32°F | 0°C | 273.15 K |
| 527.67°R | 68°F | 20°C | 293.15 K |
| 558.27°R | 98.6°F | 37°C | 310.15 K |
| 671.67°R | 212°F | 100°C | 373.15 K |
| 1000°R | 540.33°F | 282.41°C | 555.56 K |
| 1500°R | 1040.33°F | 560.19°C | 833.33 K |
| 2000°R | 1540.33°F | 837.96°C | 1111.11 K |
| 5000°R | 4540.33°F | 2504.63°C | 2777.78 K |
The Rankine scale is primarily used in engineering and thermodynamics — particularly in the United States where Fahrenheit is the standard everyday scale. Here are the most common situations where Fahrenheit to Rankine conversion is required.
Rankine is the preferred absolute temperature scale in US engineering thermodynamics. When working with equations of state, entropy, and enthalpy in US customary units, absolute temperature in Rankine is required — just as Kelvin is required for SI unit calculations. Converting from a measured Fahrenheit temperature to Rankine is a routine first step in thermodynamic analysis.
The aerospace industry in the United States historically uses Rankine in thermodynamic calculations involving engine cycles, gas turbines, and rocket propulsion. The ideal gas law — pV = nRT — requires absolute temperature, making Rankine the US engineering choice when working with Fahrenheit-based measurements. Engine operating temperatures in °F are frequently converted to °R for thermodynamic analysis.
The ideal gas law (pV = nRT) requires absolute temperature — either Kelvin or Rankine. When pressure is in psi and volume in cubic feet (US customary units), Rankine must be used as the temperature unit. For example, a gas at 72°F (531.67°R) in a US-unit calculation requires the Rankine value. This conversion also pairs naturally with pressure unit conversions such as atmospheres to Pascals.
Chemical plants and refineries in the United States often operate using US customary units. Process engineers converting temperature data from instrumentation (in °F) to absolute values for thermodynamic modelling use Rankine. Steam tables in US customary units list temperatures in both Fahrenheit and Rankine to support this need in industrial boiler and turbine calculations.
Engineering students in the United States studying thermodynamics, fluid mechanics, and heat transfer frequently encounter Rankine in US-unit textbook problems. Understanding the relationship between Fahrenheit and Rankine — and between Rankine and Kelvin — is a fundamental skill tested in engineering exams. Thermal energy problems often also involve BTU to Joules conversion alongside temperature conversion.
In cryogenic engineering — the study of very low temperatures — absolute scales are essential because negative temperatures are not physically meaningful for thermodynamic quantities like entropy. Rankine expresses cryogenic temperatures as small positive numbers. For example, liquid nitrogen at −320°F = 139.67°R, and liquid helium at −452.1°F = 7.57°R.
The National Institute of Standards and Technology provides authoritative reference data on temperature scales, SI units, and thermodynamic constants including the exact value of absolute zero used in all temperature conversions.
Visit NIST →Learn about the Rankine thermodynamic cycle — the theoretical framework underpinning steam turbines and power generation, where the Rankine temperature scale is frequently used for US-unit engineering analysis.
Read on Wikipedia →Need to convert between Celsius, Fahrenheit, Kelvin, and Rankine all at once? Explore the full suite of temperature conversion tools on ConcreteMetric for fast, accurate results in any direction.
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