Fahrenheit to Kelvin Calculator — Convert °F to K Instantly
Type a Fahrenheit reading — from a 72°F living room to a 1000°F kiln — and get kelvins the instant you hit the key. Free, exact, and built for American students, engineers, and labs working with SI data.
Ultimate 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 keep it the everyday standard in American homes.
Where it is used: Everyday weather forecasts, oven recipes, and clinical thermometers across the United States; also still appears on older equipment in a few other countries.
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, cryogenics, astrophysics, and any calculation that needs absolute temperature — including every US research journal and standards body.
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
Lab notebooks in °F, journals in K
A benchtop data-logger at a university lab records 68°F, but the journal requires SI units — one entry delivers exactly 293.15 K for the results table, no Celsius detour.
Heat-duty calcs on US process data
A line at a Gulf Coast refinery runs at 300°F; fed in as 422.04 K, every downstream gas-law figure stays in clean SI units.
Melting points across unit systems
US forging shops quote 2800°F while SI phase diagrams chart iron at 1811 K — the direct conversion (2800°F = 1810.93 K) confirms the alloy is fully molten with a single entry.
Low-temperature physics
A cryocooler spec sheet lists a cold finger at -452°F; converted to about 4.26 K, it's instantly flagged as liquid-helium-range equipment for the lab inventory at a national lab.
Related Temperature Conversions
How to Use
-
1
Enter the Fahrenheit Value
Type the reading straight off your US thermometer — say, 72 for a comfortable Phoenix winter afternoon
-
2
See the Kelvin Result
The absolute temperature appears instantly: 72°F = 295.37 K, ready for any SI thermodynamic calculation
-
3
Copy or Swap
Copy the result into your lab notebook or report, or hit Swap to convert Kelvin back to Fahrenheit
-
4
Check the Reference Table
Scan the table for anchors like 32°F = 273.15 K (water freezes) or -459.67°F = 0 K (absolute zero)
Why Use Be Converter?
No Celsius Detour
Convert a 90°F Dallas summer afternoon or a -20°F Minnesota cold snap straight to kelvins as you type — no intermediate stop at Celsius
Exact Combined Formula
Applies K = (°F - 32) × 5/9 + 273.15 exactly — so a 212°F rolling boil on the stove returns precisely 373.15 K, every single time
Cross-System Reference Table
Everyday US anchors at a glance — absolute zero (-459.67°F = 0 K), a 32°F icy morning (273.15 K), and a 2800°F forge (≈ 1811 K, iron's melting point)
Swap with One Click
Flip to Kelvin-to-Fahrenheit instantly when an SI datasheet from a supplier has to be entered into a US-calibrated controller
Free & No Signup
Unlimited conversions for lab benches, plant floors, and classrooms — from high-school chemistry to ASME engineering reports. Always free, no account
Runs Locally
Every calculation happens right in your browser. Your temperature data never leaves your device — nothing is sent to any server
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
This free online converter takes any reading from America's everyday scale — the one on your thermostat, oven dial, and car dashboard — and returns the SI absolute value in a single step using K = (°F - 32) × 5/9 + 273.15. Whether you're preparing a manuscript for a US journal that requires SI units, running heat-duty calculations on refinery process data, checking forging specs against Kelvin-based phase diagrams, or spec'ing cryogenic equipment, you get instant, exact answers. The Fahrenheit scale, published by Daniel Gabriel Fahrenheit in 1724, still governs daily weather and cooking across the United States; the kelvin, proposed by Lord Kelvin in 1848 and now an SI base unit, governs science worldwide. This tool is the fastest bridge between the two.
Expert Tips for Fahrenheit to Kelvin Conversion
Order matters: subtract 32 first, then multiply by 5/9. Skip the subtraction and you'll land about 17.8 K too high — a classic slip in rushed lab math before an exam.
Commit the bridge anchors to memory: -459.67°F = 0 K (absolute zero), 32°F = 273.15 K (water freezes), 98.6°F = 310.15 K (body temp), 212°F = 373.15 K (rolling boil).
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) come out as whole numbers.
Handy high-temperature references for the shop floor: 1000°F = 810.93 K, 2000°F = 1366.48 K, and 2800°F = 1810.93 K — right at iron's melting point for forge and foundry work.
On US engineering drawings and reports, list both units side by side and double-check with the Swap button; mixing up the 5/9 and 9/5 factors is the most common °F-to-K mistake we see.