Converting Celsius to Fahrenheit is quick and simple with a reliable formula or a handy mental shortcut. Direct method (exact)

• Use the formula: Fahrenheit = Celsius × 9/5 + 32
• In decimal form: Fahrenheit = Celsius × 1.8 + 32
• Example: 25°C → 25 × 1.8 + 32 = 45 + 32 = 77°F

Easy mental shortcut (rough but fast)

• Double the Celsius value and then add 30.
• Fahrenheit ≈ (Celsius × 2) + 30
• Example: 25°C → 25 × 2 + 30 = 50 + 30 = 80°F (close to 77°F)

Tips

• For common temperatures, memorize a few reference points (0°C = 32°F, 100°C = 212°F) to check your quick estimates.
• When you need precision, rely on the exact formula and a calculator if possible.