Temperature Converter
Convert between temperature units
About the Calculator
Temperature conversions show up in everyday life more than people expect. This converter makes it easy to move between Celsius, Fahrenheit, and Kelvin without memorizing formulas. Use it when you are traveling, checking a recipe, or reading a weather report in a different scale. It is also useful for students and science work, since Kelvin is the standard in many formulas. Enter a value, pick the units, and you get an instant answer you can trust. It saves time and helps you avoid common mistakes like mixing scales. When the numbers are clear, decisions feel simpler, whether you are cooking, studying, or planning a trip.
How to Calculate Manually
- 1Celsius to Fahrenheit: Multiply by 9/5 (or 1.8), then add 32.
- 2Fahrenheit to Celsius: Subtract 32, then multiply by 5/9.
- 3Celsius to Kelvin: Add 273.15.
- 4Kelvin to Celsius: Subtract 273.15.
- 5For Fahrenheit to Kelvin, first convert to Celsius, then to Kelvin.
25°C
77.00°F
Reference Points
The Formula
Examples
Convert 25°C to Fahrenheit
(25 × 9/5) + 32 = 45 + 32 = 77°F
Convert 98.6°F to Celsius
(98.6 - 32) × 5/9 = 66.6 × 0.556 = 37°C
Convert 0°C to Kelvin
0 + 273.15 = 273.15 K
Tips & Strategies
Quick tip. Normal body temperature is 98.6°F or 37°C.
Quick tip. Water freezes at 32°F / 0°C and boils at 212°F / 100°C.
Quick tip. Absolute zero (0 K) is -273.15°C or -459.67°F.
Quick tip. The two scales meet at -40: -40°C = -40°F.
Cross-check when the decision matters. Run a second scenario with rounded inputs or a different path to the same quantity so you do not rely on a single fragile chain of arithmetic.
Things Worth Knowing
- •The Fahrenheit freezing point mistake: Daniel Fahrenheit set 0°F as the coldest temperature he could create (salt-ice mixture) and 96°F as human body temperature; but he miscalculated body temp (actually 98.6°F), making his scale based on errors that stuck for 300 years.
- •The only temperature all scales agree: at -40 degrees, Fahrenheit and Celsius are exactly the same (-40°F = -40°C), the only point where both scales intersect, creating the world's most useless temperature trivia fact.
- •Absolute zero can never be reached: absolute zero (-273.15°C or -459.67°F or 0 Kelvin) is theoretically the coldest possible temperature where atoms stop moving; but quantum mechanics prevents us from ever actually reaching it, only getting extremely close (scientists have achieved 0.0000000001 K).
- •The world uses Celsius... except: only 7% of the world's population uses Fahrenheit (US, some Caribbean islands, Palau, Micronesia) while 93% uses Celsius; yet US weather forecasts, cooking recipes, and medical thermometers remain stubbornly Fahrenheit.
- •The sun's core temperature: the sun's core is approximately 15 million °C (27 million °F); but the surface is only 5,500°C (9,932°F), while the corona (outer atmosphere) mysteriously spikes back up to 1-2 million °C, a puzzle scientists are still trying to solve.