18°C to °F — What is 18 Celsius in Fahrenheit?
18°C = 64.40°F. Use the exact formula (°C × 9/5) + 32 to convert any Celsius temperature to Fahrenheit — algebraically exact with zero rounding, as defined by the NIST.
Answer
18 °C = 64.40 °F
Exact: 64.400000 °F · uses the BIPM-defined constant
How it's calculated
(°C × 9/5) + 32 = °F
Step 1: Apply the formula to the input value.
Step 2: (18 × 9/5) + 32 = 32.4 + 32 = 64.40
What does 18°C feel like?
18°C is cool to mild. European heating standards require indoor temperatures of at least 18°C for habitation. 18°C is comfortable for physical activity but chilly for rest indoors without heating.
18°C in other temperature scales
Celsius
18°C
Fahrenheit
64.40°F
Kelvin
291.15 K
Common temperature references
Key temperatures from science, cooking, and medicine
| °C | °F | Reference |
|---|---|---|
| -40°C | -40°F | °C and °F are equal |
| -18°C | 0°F | Zero Fahrenheit |
| 0°C | 32°F | Water freezes |
| 10°C | 50°F | Cool day |
| 20°C | 68°F | Room temperature |
| 25°C | 77°F | Warm room |
| 37°C | 98.6°F | Body temperature |
| 38°C | 100.4°F | Fever threshold (WHO) |
| 100°C | 212°F | Water boils (sea level) |
| 160°C | 320°F | Low oven |
| 180°C | 356°F | Moderate oven (Gas Mark 4) |
| 200°C | 392°F | Hot oven (Gas Mark 6) |
| 220°C | 428°F | Very hot oven (Gas Mark 7) |
| 250°C | 482°F | Max home oven |
Celsius to Fahrenheit — Nearby Values
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Common questions about 18 °C to °F
What is 18°C in Fahrenheit?
18 degrees Celsius equals exactly 64.4 degrees Fahrenheit. The formula is (18 × 9/5) + 32 = 64.4°F. In Kelvin, this is 291.15 K.
How do you convert 18°C to °F step by step?
Step 1: Multiply 18 by 9/5 (or 1.8) to get 32.4. Step 2: Add 32. Result: 32.4 + 32 = 64.4°F. This formula is algebraically exact — zero rounding at any step.
Is 18°C hot or cold?
18°C is cool and comfortable — typical of mild spring or autumn days.
What is 64.4°F back in Celsius?
64.4°F converts back to exactly 18°C — which is 18°C. The conversion is perfectly reversible using the inverse formula: (°F − 32) × 5/9.
What should I wear at 18°C?
At 18°C, light layers work well — a long-sleeve shirt or light sweater. Bring a jacket for evenings. Comfortable for walking and light outdoor activity.
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Fahrenheit
18 °C=64.40 °F
Formula used
(°C × 9/5) + 32 = °F
Algebraically exact — zero rounding in the formula