Convert between Fahrenheit, Celsius, and Kelvin instantly. Perfect for cooking, travel, science, and weather.
C = (F - 32) × 5/9 | F = C × 9/5 + 32 | K = C + 273.15Temperature conversion between Fahrenheit, Celsius, and Kelvin uses three linear formulas. All conversions go through Celsius as the intermediate unit: your input is first converted to Celsius, then to the other two temperature scales so you can see the equivalent values side by side.
| Symbol | Meaning |
|---|---|
| F | Fahrenheit temperature |
| C | Celsius temperature |
| K | Kelvin temperature |
Our calculations are based on established financial and scientific formulas. The following sources inform the default values and methodology used in this calculator:
Convert Celsius, Fahrenheit, and Kelvin with these core relationships: F = (C x 9/5) + 32, C = (F - 32) x 5/9, and K = C + 273.15. The scales meet at -40 (the same on Celsius and Fahrenheit). Keeping a few anchor points in mind lets you estimate conversions without a calculator. Fahrenheit is used mainly in the United States, while Celsius is the standard everywhere else and in science; Kelvin, which starts at absolute zero (-273.15°C), is reserved for physics and engineering. Two useful mental shortcuts: to convert Celsius to Fahrenheit, double it and add 30 for a close estimate, and for Fahrenheit to Celsius, subtract 30 and halve. Knowing these anchors — 0°C is freezing, 20°C is comfortable room temperature, 37°C is body temperature, and 100°C is boiling — covers most everyday conversion needs. For a final check, compare your result against the anchor table above so a slipped formula or a doubled operation is spotted before you act on the number.
| Celsius | Fahrenheit | Kelvin | Context |
|---|---|---|---|
| -40 | -40 | 233 | Same on both scales |
| 0 | 32 | 273 | Water freezes |
| 20 | 68 | 293 | Room temperature |
| 37 | 98.6 | 310 | Body temperature |
| 100 | 212 | 373 | Water boils |
Conversion is most useful when a temperature carries consequences. The thresholds below are the ones worth memorizing because crossing them changes what you do — pull food from the oven, take a sick day, or bring plants inside. Food values are the USDA safe minimum internal temperatures; fever values are the standard adult thresholds used in clinical guidance.
| Threshold | Celsius | Fahrenheit | Why It Matters |
|---|---|---|---|
| Poultry, safe done | 74°C | 165°F | USDA minimum — kills salmonella |
| Ground meat, safe done | 71°C | 160°F | USDA minimum |
| Whole cuts of beef/pork | 63°C + 3 min rest | 145°F + 3 min rest | USDA minimum with rest time |
| Danger zone (food) | 4-60°C | 40-140°F | Bacteria multiply fastest here; 2-hour limit |
| Fever (adult) | 38°C | 100.4°F | Standard clinical fever threshold |
| High fever (adult) | 39.4°C | 103°F | Seek medical advice |
| Hypothermia (core) | <35°C | <95°F | Medical emergency |
| Heat warning (ambient) | ≥32°C | ≥90°F | Limit exertion; heat illness risk rises |
| Frostbite risk (exposed skin) | ≤-18°C wind chill | ≤0°F | Skin can freeze in 30 minutes |
Notice how many of these numbers are approximate by nature: oven dials run 10-20 degrees off their setting, fever readings vary by measurement site (rectal runs higher than oral), and wind chill matters more than air temperature for frostbite. Use the converter for the arithmetic, but trust a probe thermometer for food and a proper thermometer for body temperature — the stakes justify the instrument.
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Rates verified 2026-10-09 · Sourced from official seller fee schedules