How do I convert Celsius to Fahrenheit quickly?

Formula: °F = (°C × 9/5) + 32. Quick method: double the Celsius, subtract 10%, add 32. Example: 20°C = (20 × 2) - 4 + 32 = 68°F. Exact: 20°C = (20 × 1.8) + 32 = 68°F. This conversion is essential for cooking, weather, and travel between metric and imperial countries.

What are some important temperature reference points?

Water freezes: 0°C = 32°F = 273.15K. Water boils: 100°C = 212°F = 373.15K. Body temperature: 37°C = 98.6°F = 310.15K. Room temperature: 20-22°C = 68-72°F. Oven baking: 175°C = 350°F. These references help estimate and verify conversions in daily life.

When should I use Kelvin instead of Celsius or Fahrenheit?

Use Kelvin for scientific calculations, thermodynamics, and when absolute zero matters. Kelvin starts at absolute zero (-273.15°C or -459.67°F). No negative Kelvin temperatures exist. Essential in physics, chemistry, and engineering. For daily use, stick to Celsius or Fahrenheit depending on your location.

How do I convert Fahrenheit to Celsius?

Formula: °C = (°F - 32) × 5/9. Example: 68°F = (68 - 32) × 5/9 = 36 × 0.556 = 20°C. Quick estimate: subtract 30 and divide by 2. This gives a rough approximation. For cooking precision, use the exact formula. Essential for following international recipes and weather reports.

What oven temperatures should I use for different cooking methods?

Low: 150°C (300°F) for slow roasting. Medium: 175-190°C (350-375°F) for most baking. High: 200-220°C (400-425°F) for quick roasting. Very high: 230°C+ (450°F+) for pizza, bread. Always preheat to desired temperature. Oven thermometers help verify accuracy - many ovens run hot or cold.

How do weather temperatures feel in different scales?

Comfort zone: 18-24°C (64-75°F). Hot day: 30°C+ (86°F+). Cold day: below 10°C (50°F). Freezing: 0°C (32°F). Dangerous heat: 40°C+ (104°F+). Dangerous cold: -18°C (0°F). Understanding these ranges helps interpret weather forecasts when traveling internationally.

What are the differences between temperature scales?

Celsius: Water freezes at 0°, boils at 100°. Used worldwide except US. Fahrenheit: Water freezes at 32°, boils at 212°. Used in US, some Caribbean. Kelvin: Absolute scale starting at absolute zero. No degree symbol. Same increments as Celsius but offset by 273.15.

How do I handle negative temperatures in conversions?

Apply the same formulas but be careful with signs. -10°C = (-10 × 1.8) + 32 = 14°F. -10°F = (-10 - 32) × 5/9 = -23.3°C. Negative Kelvin is impossible (absolute zero is 0K). Double-check calculations with negative numbers - errors are common.

What temperature conversions are important for food safety?

Danger zone: 4-60°C (40-140°F) where bacteria multiply rapidly. Refrigerator: 4°C (40°F) or below. Freezer: -18°C (0°F) or below. Safe internal temperatures: chicken 74°C (165°F), beef 63°C (145°F), ground meat 71°C (160°F). Use thermometers for food safety.

How accurate do temperature conversions need to be?

Cooking: ±5°C (±10°F) usually acceptable for most recipes. Baking: ±2-3°C (±5°F) for best results. Scientific work: Use exact formulas and appropriate precision. Weather: ±1°C (±2°F) for practical purposes. Medical: Use exact measurements and calibrated thermometers. Round appropriately for your use case.

Temperature Converter

Convert between Celsius, Fahrenheit, Kelvin, Rankine, and Réaumur temperature scales.

Convert Temperature

Temperature Value

From Unit

Conversion Results

Fahrenheit(°F)

68°F

Kelvin(K)

293.15K

Rankine(°R)

527.67°R

Réaumur(°Ré)

16°Ré

Temperature Context

Comfortable room temperature

Common Temperatures

Water freezes

0°C

32°F, 273.15K

Room temperature

20°C

68°F, 293.15K

Body temperature

37°C

98.6°F, 310.15K

Water boils

100°C

212°F, 373.15K

C = F crossing

-40°C

-40°F, 233.15K

Absolute zero

-273.15°C

-459.67°F, 0K

Temperature Scales

Celsius (°C)

Water freezes at 0°C, boils at 100°C. Most common worldwide.

Fahrenheit (°F)

Water freezes at 32°F, boils at 212°F. Used primarily in the US.

Kelvin (K)

Absolute temperature scale starting at absolute zero. Used in science.

Rankine (°R)

Absolute scale based on Fahrenheit degrees. Used in engineering.

Réaumur (°Ré)

Historical scale where water freezes at 0° and boils at 80°.

Quick Formulas

°C to °F:
°F = (°C × 9/5) + 32

°F to °C:
°C = (°F - 32) × 5/9

°C to K:
K = °C + 273.15

K to °C:
°C = K - 273.15