Celsius to Fahrenheit Converter
Formula: °F = (°C × 9/5) + 32 | °C = (°F − 32) × 5/9
Common temperatures — tap a row to load it
| Celsius | Fahrenheit | What it means |
|---|---|---|
| −40 °C | −40 °F | The one point where both scales agree |
| 0 °C | 32 °F | Water freezes |
| 20 °C | 68 °F | Room temperature |
| 25 °C | 77 °F | Comfortable warm day |
| 37 °C | 98.6 °F | Normal body temperature |
| 100 °C | 212 °F | Water boils |
The conversion runs entirely in your browser — nothing you type is uploaded or stored.
This free Celsius to Fahrenheit converter turns any temperature in degrees Celsius into degrees Fahrenheit instantly — and back again. It is the conversion people look up most often when they travel, cook from a recipe written abroad, read a weather forecast for the United States, or check a fever reading: most of the world uses Celsius, while the United States still reports weather, oven temperatures and body temperature in Fahrenheit.
The maths is one multiplication and one addition, always in this order: multiply the Celsius temperature by 9/5 (the same as 1.8), then add 32. So 25 °C becomes 25 × 1.8 = 45, plus 32 = 77 °F. The 9/5 stretches each Celsius degree to its larger Fahrenheit size — there are 180 Fahrenheit degrees between the freezing and boiling points of water, against 100 Celsius degrees — and the +32 shifts the result because Fahrenheit puts the freezing point of water at 32, not at zero. The converter also shows the Kelvin value, the scale scientists use, which is simply the Celsius value plus 273.15.
Two temperatures are worth remembering. Water freezes at 0 °C (32 °F) and boils at 100 °C (212 °F), and −40 is the single point where both scales show the same number: −40 °C = −40 °F. The table above covers the values people actually type — weather, room temperature, body temperature and oven settings — and tapping any row loads it into the converter.
How to use
- Type a temperature in the Celsius box — the Fahrenheit and Kelvin results update as you type.
- Or type in the Fahrenheit box instead, and the Celsius value is worked out for you.
- Tap any row in the common-temperatures table to load a familiar value, for example 37 °C for body temperature.
- Use the formula line to check the maths yourself: °F = (°C × 9/5) + 32.
Frequently asked questions
What is the formula to convert Celsius to Fahrenheit?
Multiply the Celsius temperature by 9/5 (or 1.8) and add 32: °F = (°C × 9/5) + 32. For example, 20 °C × 1.8 = 36, plus 32 = 68 °F.
How do I convert Fahrenheit back to Celsius?
Reverse the steps in reverse order: subtract 32 first, then multiply by 5/9. The formula is °C = (°F − 32) × 5/9 — so 77 °F becomes (77 − 32) × 5/9 = 25 °C.
What temperature is the same in Celsius and Fahrenheit?
−40 is the only temperature where both scales agree: −40 °C = −40 °F. At any value above −40, the same number is hotter in Celsius than in Fahrenheit.
Is 37 °C a normal body temperature?
Yes — 37 °C equals 98.6 °F, the standard reference for normal human body temperature. A reading of 38 °C (100.4 °F) is the usual fever threshold.
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