How to convert Celsius to Fahrenheit
- Celsius and Fahrenheit are already selected as From and To.
- Type the temperature in Value. Negative numbers work, for example −5.
- Read the Result in °F. The line underneath repeats the full conversion and the formula.
- Press the swap button to convert Fahrenheit to Celsius, or pick Kelvin from either list.
Features
- Exact formulas for all six pairs of Celsius, Fahrenheit and Kelvin.
- Formula shown for the chosen direction, so you can learn it or check homework.
- Quick table of body, fever, weather and cooking temperatures.
- Absolute zero warning for temperatures that can't exist.
- Negative and decimal temperatures such as −17.8 or 38.5.
The Celsius to Fahrenheit formula
°F = (°C × 9/5) + 32
To go from C to F, multiply the Celsius temperature by 9, divide by 5, then add 32. Multiplying by 1.8 is the same as the first two steps. Worked example for 25 °C: 25 × 9 = 225, 225 ÷ 5 = 45, and 45 + 32 = 77 °F. To go back, the formula is °C = (°F − 32) × 5/9. For a quick estimate, double the Celsius figure and add 30: 20 °C becomes 70 °F, close to the exact 68 °F.
Body temperature and fever in °C and °F
Thermometers sold in different countries show different scales, and advice found online often mixes them. These conversions come up again and again:
- 36.5 °C is 97.7 °F
- 37 °C is 98.6 °F
- 37.5 °C is 99.5 °F
- 38 °C is 100.4 °F
- 38.5 °C is 101.3 °F
- 39 °C is 102.2 °F
- 40 °C is 104 °F
A change of 1 °C is a change of 1.8 °F, so a temperature that rises from 37 to 39 °C has gone up by 3.6 °F. The converter only does the arithmetic; it does not give medical advice.
Weather temperatures
For weather, remember a few anchor points: 0 °C is 32 °F (freezing), 10 °C is 50 °F (cool), 20 °C is 68 °F (mild), 30 °C is 86 °F (hot) and 40 °C is 104 °F, a common summer high in Lahore, Delhi or Monterrey. A forecast of −10 °C is 14 °F.
Why the numbers look so different
The two scales start from different zero points and use different step sizes. Celsius puts water's freezing point at 0 and boiling point at 100, a gap of 100 degrees. Fahrenheit puts them at 32 and 212, a gap of 180 degrees. That is where the 9/5 comes from, and the + 32 lines up the starting points. Kelvin uses Celsius-sized steps but starts at absolute zero, so K = °C + 273.15.
Why use Fileora's temperature converter
You get an exact result, the formula and a table of the temperatures people actually look up, all in one place, with nothing to install or sign up for. It works offline once loaded and keeps nothing you enter.
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