Whether you are checking the weather for a trip abroad, following a recipe from an American cookbook, or taking someone's temperature, knowing how to convert Celsius to Fahrenheit is an essential everyday skill. This guide explains the exact formula, gives you worked examples, and provides a handy reference chart.
The Celsius to Fahrenheit Formula
°F = (°C × 9/5) + 32This formula does two things: multiplying by 9/5 (= 1.8) accounts for the difference in scale between degrees, then adding 32 shifts the baseline — because Celsius sets 0° at water's freezing point while Fahrenheit sets it at 32°.
Step-by-Step Worked Examples
Example 1: Convert 25°C (warm summer day)
°F = (25 × 9/5) + 32 = (25 × 1.8) + 32 = 45 + 32 = 77°FExample 2: Convert 100°C (boiling point of water)
°F = (100 × 1.8) + 32 = 180 + 32 = 212°FExample 3: Convert 37°C (normal body temperature)
°F = (37 × 1.8) + 32 = 66.6 + 32 = 98.6°FThe Reverse Formula: Fahrenheit to Celsius
°C = (°F − 32) × 5/9Example: 68°F → (68 − 32) × 5/9 = 36 × 0.5556 = 20°C
Quick Mental Math Shortcut
For rough estimates: Double the Celsius value and add 30. At 22°C: (22 × 2) + 30 = 74°F (actual: 71.6°F). The error is typically within 2–3°F for normal weather temperatures.
Common Temperature Conversions Chart
| °C | °F | Context |
|---|---|---|
| −40°C | −40°F | The only point where both scales are equal |
| 0°C | 32°F | Water freezing point |
| 10°C | 50°F | Cool autumn day |
| 20°C | 68°F | Comfortable room temperature |
| 25°C | 77°F | Warm summer day |
| 37°C | 98.6°F | Normal body temperature |
| 38°C | 100.4°F | Fever threshold |
| 40°C | 104°F | Very hot / high fever |
| 100°C | 212°F | Water boiling point |
| 180°C | 356°F | Typical baking temperature |
Cooking Temperature Conversions
| °F | °C | Description |
|---|---|---|
| 325°F | 165°C | Slow oven |
| 350°F | 175°C | Moderate oven (most common) |
| 400°F | 200°C | Hot oven |
| 450°F | 230°C | Very hot oven |
Frequently Asked Questions
What is 30°C in Fahrenheit?
(30 × 1.8) + 32 = 54 + 32 = 86°F.
What temperature is the same in Celsius and Fahrenheit?
−40° is the only point where both scales read the same number.
Is 37°C a fever?
37°C (98.6°F) is normal body temperature. A fever in adults is typically 38°C (100.4°F) or higher.
Use our free Temperature Converter to convert any temperature instantly.