Fahrenheit to Kelvin Converter
Convert Fahrenheit to Kelvin instantly with our free online tool. Built for science and engineering across unit systems.
Temperature ConverterThe quick answer for 1 Fahrenheit — type any value below for the exact result
Fahrenheit
Kelvin
Fahrenheit to Kelvin Conversion Formula
Fahrenheit and Kelvin Explained
Fahrenheit (f)
The Fahrenheit scale (symbol °F) sets water's freezing point at 32° and its boiling point at 212°, placing exactly 180 degrees between them. Its zero was calibrated against the coldest brine mixture Daniel Gabriel Fahrenheit could produce, which conveniently maps everyday weather onto a 0-to-100 band. One Fahrenheit degree equals five-ninths of a Celsius degree, giving finer graduations on oven dials and thermostats — the devices that still make it the everyday US standard.
Where it is used: Weather, cooking, and clinical temperatures in the United States and a few territories; also still appears on older UK and Canadian equipment.
Origin: Daniel Gabriel Fahrenheit, a Polish-born Dutch instrument maker, published the scale in 1724; his precision mercury thermometers carried it across the English-speaking world.
Kelvin (k)
The kelvin (symbol K, no degree sign) is the SI base unit of thermodynamic temperature, anchored to absolute zero and defined since 2019 by an exact value of the Boltzmann constant. Water freezes at 273.15 K and boils at 373.15 K, and each kelvin step is the same size as a Celsius degree — but unlike Fahrenheit or Celsius, the scale never goes below zero. That makes it the required input for gas laws, radiation laws, and every formula where energy scales with true temperature.
Where it is used: Science and engineering worldwide: thermodynamics, cryophysics, astrophysics, and any calculation that needs absolute temperature.
Origin: Lord Kelvin proposed the absolute scale in 1848; it became an SI base unit in 1960, lost its degree symbol in 1968, and was redefined via the Boltzmann constant in 2019.
Fahrenheit to Kelvin Conversion Table
| Fahrenheit (f) | Kelvin (k) |
|---|---|
| -459.67 f | 0 k |
| -40 f | 233.15 k |
| -20 f | 244.2611111111 k |
| 0 f | 255.3722222222 k |
| 10 f | 260.9277777778 k |
| 20 f | 266.4833333333 k |
| 32 f | 273.15 k |
| 50 f | 283.15 k |
| 68 f | 293.15 k |
| 70 f | 294.2611111111 k |
| 80 f | 299.8166666667 k |
| 90 f | 305.3722222222 k |
| 98.6 f | 310.15 k |
| 100 f | 310.9277777778 k |
| 120 f | 322.0388888889 k |
| 212 f | 373.15 k |
| 350 f | 449.8166666667 k |
| 500 f | 533.15 k |
| 1000 f | 810.9277777778 k |
| 5000 f | 3033.15 k |
Kelvin to Fahrenheit Conversion Table
| Kelvin (k) | Fahrenheit (f) |
|---|---|
| 0 k | -459.67 f |
| 77 k | -321.07 f |
| 233.15 k | -40 f |
| 255.372 k | -0.0004 f |
| 273.15 k | 32 f |
| 293.15 k | 68 f |
| 298.15 k | 77 f |
| 300 k | 80.33 f |
| 310.15 k | 98.6 f |
| 373.15 k | 212 f |
| 933 k | 1219.73 f |
| 1337 k | 1946.93 f |
| 1811 k | 2800.13 f |
| 5772 k | 9929.93 f |
Fahrenheit to Kelvin in Everyday Objects
Common real-world examples that make Fahrenheit and Kelvin easy to picture at a glance.
| Fahrenheit (f) | Kelvin (k) | |
|---|---|---|
| Absolute zero | -459.67 f | 0 k |
| Alaska all-time record low | -80 f | 210.9277777778 k |
| Water freezing point | 32 f | 273.15 k |
| Comfortable room thermostat | 70 f | 294.2611111111 k |
| Human body temperature | 98.6 f | 310.15 k |
| Water boiling point | 212 f | 373.15 k |
| Incandescent bulb filament | 4580.33 f | 2800 k |
| Sun surface temperature | 9929.93 f | 5772 k |
When You Need Fahrenheit to Kelvin Conversions
US instruments, SI manuscripts
A bench data-logger records 68°F, but the journal wants SI units — one entry converts it to exactly 293.15 K for the results table without a Celsius middle step.
Thermodynamics with US-sourced data
Heat-duty and gas-law calculations demand absolute temperature: a process line running at 300°F feeds in as 422.04 K, keeping every downstream figure in clean SI units.
Melting points across unit systems
US forging specs quote 2800°F while SI phase diagrams chart iron at 1811 K — the direct conversion (2800°F = 1810.93 K) confirms the alloy will be fully molten with one entry.
Low-temperature physics
Cryocooler spec sheets mix systems: a cold finger rated at -452°F converts to about 4.26 K, instantly flagging it as liquid-helium-range equipment for the lab inventory.
How to Use
-
1
Enter the Fahrenheit Value
Type the temperature as read in the US system — for example, enter 70 for a comfortable room at 70°F
-
2
See the Kelvin Result
The absolute temperature appears instantly: 70°F = 294.26 K, ready for any SI thermodynamic calculation
-
3
Copy or Swap
Copy the result or click Swap to convert Kelvin back to Fahrenheit
-
4
Check the Reference Table
Browse the table for anchors like 32°F = 273.15 K (ice melts) or -459.67°F = 0 K (absolute zero)
Why Use Be Converter?
Skip the Two-Step Detour
Go straight from a US thermometer reading like 70°F to 294.26 K in real time — no middle trip through Celsius
Exact Combined Formula
Applies K = (°F - 32) × 5/9 + 273.15 exactly, so 212°F returns precisely 373.15 K every time
Cross-System Reference Table
Bridge anchors at a glance — absolute zero (-459.67°F = 0 K), ice melting (32°F = 273.15 K), and iron melting (2800°F ≈ 1811 K)
Swap with One Click
Flip to Kelvin to Fahrenheit instantly when an SI datasheet has to be dialed into a US-calibrated controller
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Frequently Asked Questions
What is the formula to convert Fahrenheit to Kelvin?
What is 32°F in Kelvin?
What is absolute zero in Fahrenheit?
What is body temperature in Kelvin?
Can I convert Fahrenheit to Celsius first?
What is 1000°F in Kelvin?
What is 0°F in Kelvin?
How hot is the surface of the sun in Fahrenheit and Kelvin?
About Fahrenheit to Kelvin Converter
Our free online Fahrenheit to Kelvin converter jumps directly from the US temperature scale to the SI absolute scale in one step, using the combined formula K = (°F - 32) × 5/9 + 273.15. Whether you are folding US instrument logs into a journal manuscript, feeding a heat-duty calculation with Fahrenheit process data, comparing forging specs against Kelvin phase diagrams, or sizing cryogenic equipment, this tool delivers instant, exact results. The Fahrenheit scale, published by Daniel Gabriel Fahrenheit in 1724, and the Kelvin scale, established by Lord Kelvin in 1848 and now an SI base unit, sit at opposite ends of the measurement world — this converter is the shortest path between them.
Expert Tips for Fahrenheit to Kelvin Conversion
Order matters: subtract 32 before multiplying by 5/9. Skipping the subtraction puts you about 17.8 K high, a classic error in rushed lab math.
Memorize the bridge anchors: -459.67°F = 0 K (absolute zero), 32°F = 273.15 K (freezing), 98.6°F = 310.15 K (body temperature), 212°F = 373.15 K (boiling).
Some readings land on clean values: 68°F converts to exactly 293.15 K and 5000°F to exactly 3033.15 K, because their Celsius equivalents (20°C and 2760°C) are whole numbers.
High-temperature engineering references: 1000°F = 810.93 K, 2000°F = 1366.48 K, and 2800°F = 1810.93 K — right at iron's melting point for forge work.
In US engineering documents, report both units side by side and verify with the Swap button; mixing up the 5/9 and 9/5 factors is the most common cross-system conversion mistake.