What is the formula to convert Fahrenheit to Celsius?

To convert Fahrenheit to Celsius, subtract 32 from the Fahrenheit temperature and multiply by 5/9. Formula: °C = (°F - 32) × 5/9. For example, 68°F = (68 - 32) × 5/9 = 20°C.

What is absolute zero in different temperature scales?

Absolute zero is 0 Kelvin, -273.15°C, or -459.67°F. It's the lowest possible temperature where all molecular motion stops.

Temperature Converter - Celsius, Fahrenheit, Kelvin

What is a Temperature Converter?

A temperature converter is a tool that transforms temperature readings from one scale to another. The three most common temperature scales are Celsius (°C), Fahrenheit (°F), and Kelvin (K).

Celsius (also called Centigrade) is used by most countries worldwide and in scientific contexts. Water freezes at 0°C and boils at 100°C at standard atmospheric pressure.

Fahrenheit is primarily used in the United States for everyday temperature measurements. Water freezes at 32°F and boils at 212°F.

Kelvin is the SI unit of temperature used in scientific applications. It starts at absolute zero (0 K = -273.15°C), where all molecular motion ceases.

Temperature Conversion Formulas

Celsius Conversions

Celsius to Fahrenheit: °F = (°C × 9/5) + 32
Celsius to Kelvin: K = °C + 273.15

Fahrenheit Conversions

Fahrenheit to Celsius: °C = (°F - 32) × 5/9
Fahrenheit to Kelvin: K = (°F - 32) × 5/9 + 273.15

Kelvin Conversions

Kelvin to Celsius: °C = K - 273.15
Kelvin to Fahrenheit: °F = (K - 273.15) × 9/5 + 32

Key Reference Points

Description	Celsius	Fahrenheit	Kelvin
Absolute Zero	-273.15°C	-459.67°F	0 K
Water Freezes	0°C	32°F	273.15 K
Room Temperature	20-22°C	68-72°F	293-295 K
Body Temperature	37°C	98.6°F	310.15 K
Water Boils	100°C	212°F	373.15 K

Common Temperature Conversions

Celsius to Fahrenheit

-40°C = -40°F (where both scales meet!)
0°C = 32°F (freezing point)
10°C = 50°F (cool day)
20°C = 68°F (room temperature)
25°C = 77°F (warm day)
30°C = 86°F (hot day)
37°C = 98.6°F (body temperature)
100°C = 212°F (boiling point)

Fahrenheit to Celsius

32°F = 0°C (freezing point)
50°F = 10°C
68°F = 20°C
77°F = 25°C
86°F = 30°C
98.6°F = 37°C (body temperature)
104°F = 40°C (heat wave)
212°F = 100°C (boiling point)

Weather Temperature Guide

Below 0°C (32°F): Freezing, snow possible
0-10°C (32-50°F): Cold, coat weather
10-20°C (50-68°F): Cool, light jacket
20-25°C (68-77°F): Comfortable, pleasant
25-30°C (77-86°F): Warm, summer weather
Above 30°C (86°F): Hot, stay hydrated
Above 40°C (104°F): Extreme heat, dangerous

Frequently Asked Questions

How do I convert Celsius to Fahrenheit?

To convert Celsius to Fahrenheit, multiply the Celsius temperature by 9/5 (or 1.8) and add 32. Formula: °F = (°C × 1.8) + 32. For example, to convert 25°C: (25 × 1.8) + 32 = 45 + 32 = 77°F.

What's an easy trick to convert Celsius to Fahrenheit in my head?

For a quick approximation, double the Celsius value and add 30. For example, 20°C ≈ (20 × 2) + 30 = 70°F (actual: 68°F). This method is accurate within a few degrees for typical weather temperatures.

Why do the US and UK use different temperature scales?

The Fahrenheit scale was developed by Daniel Fahrenheit in 1724 and was widely adopted in English-speaking countries. The Celsius scale, created by Anders Celsius in 1742, became the international standard. The UK has largely switched to Celsius since the 1960s, but the US still primarily uses Fahrenheit for everyday use.

What is absolute zero?

Absolute zero is the lowest possible temperature: 0 Kelvin, -273.15°C, or -459.67°F. At this temperature, all molecular motion stops. It's physically impossible to reach absolute zero, though scientists have gotten extremely close in laboratory conditions.

At what temperature are Celsius and Fahrenheit equal?

Celsius and Fahrenheit are equal at -40 degrees. This is the only temperature where both scales show the same number: -40°C = -40°F.

What is a normal body temperature?

Normal human body temperature is approximately 37°C (98.6°F). However, it can vary slightly throughout the day and from person to person. A fever is typically defined as a body temperature above 38°C (100.4°F).

Temperature Conversion Tips

Quick C to F: Double and add 30 for a rough estimate
Quick F to C: Subtract 30 and divide by 2 for a rough estimate
Remember key points: 0°C=32°F (freezing), 100°C=212°F (boiling), 37°C=98.6°F (body)
Kelvin is easy: Just add or subtract 273.15 from Celsius
-40 is the same: Both scales meet at -40 degrees

Temperature Converter