Temperature Converter

Input Parameters

Temperature Value

°C

From Scale Celsius (°C) Fahrenheit (°F) Kelvin (K) Rankine (°R) Réaumur (°Ré) Delisle (°De) Newton (°N) Rømer (°Rø)

To Scale Celsius (°C) Fahrenheit (°F) Kelvin (K) Rankine (°R) Réaumur (°Ré) Delisle (°De) Newton (°N) Rømer (°Rø)

Decimal Precision 0 1 2 3 4

Atmospheric Pressure (kPa)

Relative Humidity (%)

Conversion Results

68.0 °F

Equivalent to 20°C / 293.15K

Temperature Scale	Value
Celsius	20.0 °C
Fahrenheit	68.0 °F
Kelvin	293.15 K
Rankine	527.67 °R

Cold Moderate Hot

Absolute Zero

-273.15°C

Freezing Point

0.0°C

Boiling Point

100.0°C

Human Body

37.0°C

Key Temperature Points:

• Absolute Zero: -273.15°C / -459.67°F

• Water Freezes: 0°C / 32°F

• Water Boils: 100°C / 212°F (at sea level)

SI Units ISO 80000-5

Temperature Converter v1.0 • SI Units • ISO 80000-5

Conversion History

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Temperature Conversion Masterclass

Your Complete Guide to Understanding and Converting Temperatures with Real-World Examples

Have you ever wondered why 20°C feels comfortable but 68°F sounds cold? Or why scientists use Kelvin instead of Celsius? Temperature conversion can be confusing, but it doesn't have to be! This guide will make you a temperature conversion expert.

Try Our Interactive Temperature Converter

Convert between 8 different temperature scales instantly with visual charts and real-time comparisons.

Why Temperature Conversion Matters

Temperature is everywhere in our lives: weather forecasts, cooking recipes, scientific research, medical readings, and even car engines. Different countries and fields use different temperature scales, making conversion essential for:

• Travel planning (Weather forecasts in different countries)
• Cooking (Recipes from around the world)
• Science and engineering (Precise measurements in research)
• Healthcare (Body temperature monitoring)
• Weather tracking (Comparing climate data)

The Three Main Temperature Scales Explained

Celsius (°C)

Used by: Most of the world (except the USA)

Key points:

• 0°C = Water freezes
• 100°C = Water boils
• 37°C = Human body temperature
• 20-25°C = Comfortable room temperature

Fahrenheit (°F)

Used by: United States, Bahamas, Cayman Islands

Key points:

• 32°F = Water freezes
• 212°F = Water boils
• 98.6°F = Human body temperature
• 68-72°F = Comfortable room temperature

Kelvin (K)

Used by: Scientists worldwide

Key points:

• 0K = Absolute zero (-273.15°C)
• 273.15K = Water freezes
• 373.15K = Water boils
• No negative temperatures

The Core Conversion Formulas (Made Simple!)

These formulas might look scary, but they're actually quite logical once you understand them. Here's the simple version:

1. Celsius to Fahrenheit: The Most Common Conversion

The Magic Formula:

°F = (°C × 9/5) + 32

Think of it as: Multiply by 1.8, then add 32

Real Example: Convert 20°C to Fahrenheit

Step 1: Multiply by 9/5 (which is 1.8)

20 × 1.8 = 36

Step 2: Add 32

36 + 32 = 68°F

So 20°C = 68°F. See? Not so hard!

2. Fahrenheit to Celsius

The Magic Formula:

°C = (°F - 32) × 5/9

Think of it as: Subtract 32, then divide by 1.8

Real Example: Convert 68°F to Celsius

Step 1: Subtract 32

68 - 32 = 36

Step 2: Multiply by 5/9 (or divide by 1.8)

36 ÷ 1.8 = 20°C

So 68°F = 20°C. Perfect match with our first example!

3. Celsius to Kelvin (Super Easy!)

The Simplest Formula:

K = °C + 273.15

Just add 273.15! That's it!

Real Example: Convert 20°C to Kelvin

20 + 273.15 = 293.15K

See? You just add 273.15. Easy!

Quick Mental Conversion Trick

For a rough Celsius to Fahrenheit conversion: Double it and add 30 (instead of 32).

Example: 20°C → 20 × 2 = 40, + 30 = 70°F (actual: 68°F - close enough!)

For Fahrenheit to Celsius: Subtract 30 and halve it.

Example: 70°F → 70 - 30 = 40, ÷ 2 = 20°C (actual: 21.1°C - good estimate!)

Common Temperature Points You Should Know

100°C / 212°F

Water boils Hot

37°C / 98.6°F

Human body temperature

20°C / 68°F

Comfortable room temperature

0°C / 32°F

Water freezes Cold

-40°C / -40°F

Where Celsius and Fahrenheit meet!

-273.15°C / 0K

Absolute zero

Specialized Temperature Scales

Beyond the big three, there are other interesting temperature scales used in specific contexts:

Scale	Inventor	Key Feature	Modern Use
Rankine (°R)	William Rankine (1859)	Fahrenheit equivalent of Kelvin	Some engineering fields in the US
Réaumur (°Ré)	René Réaumur (1731)	0°Ré = freezing, 80°Ré = boiling	Some European cheese making
Delisle (°De)	Joseph Delisle (1732)	Temperature decreases as scale increases	Historical Russian use
Newton (°N)	Isaac Newton (1701)	Based on linseed oil properties	Historical curiosity
Rømer (°Rø)	Ole Rømer (1701)	First modern temperature scale	Historical Danish use

Key Features of Our Temperature Converter

8 Different Scales

Convert between Celsius, Fahrenheit, Kelvin, Rankine, Réaumur, Delisle, Newton, and Rømer.

Visual Charts

See your conversion visually with color-coded bar charts that show relative temperatures.

History Tracking

Save your conversions and compare them over time. Perfect for tracking weather patterns or cooking experiments.

Export Results

Save conversions as PDF, HTML, or text files for reports, school projects, or sharing with friends.

Practical Temperature Conversion Examples

Cooking and Baking

Recipes often use different temperature scales:

• Baking bread: 220°C = 425°F
• Roasting chicken: 180°C = 350°F
• Simmering soup: 85°C = 185°F
• Refrigerator: 4°C = 39°F
• Freezer: -18°C = 0°F

Weather and Climate

Understanding weather forecasts:

• Hot summer day: 35°C = 95°F Hot
• Pleasant spring day: 15°C = 59°F
• Cold winter day: -5°C = 23°F Cold
• Record cold: -40°C = -40°F Extreme

Medical Temperature Quick Reference

Normal body temperature: 36.5-37.5°C = 97.7-99.5°F

Fever threshold: 38.0°C = 100.4°F

High fever: 39.5°C = 103.1°F

Hypothermia risk: Below 35.0°C = Below 95.0°F

15 Frequently Asked Questions (FAQs)

1. Why do Celsius and Fahrenheit meet at -40 degrees?

This is a mathematical coincidence. Both scales use different starting points and rate of increase, but their conversion formulas intersect exactly at -40. The equation °C = (°F - 32) × 5/9 becomes °C = (°C × 9/5 + 32 - 32) × 5/9, which solves to -40.

2. What's the difference between Celsius and Centigrade?

They're essentially the same! "Centigrade" (meaning "100 steps") was the original name. In 1948, it was officially renamed Celsius after Anders Celsius, but many people still use both terms interchangeably.

3. Why does the US still use Fahrenheit?

Historical reasons and cost of conversion. The US started using Fahrenheit before Celsius became the international standard. Changing all weather reports, appliances, road signs, and educational materials would be extremely expensive and confusing.

4. What's the advantage of Kelvin over Celsius?

Kelvin starts at absolute zero (the coldest possible temperature) and has no negative numbers, making calculations easier in physics and chemistry. Also, 1K change = 1°C change, so conversions are simple.

5. How accurate do I need to be in daily conversions?

For cooking: ±5°F is fine. For weather: ±2°F is good. For scientific work: 2 decimal places. For medical: 0.1°C precision matters.

6. Why is absolute zero -273.15°C exactly?

Absolute zero is when molecular motion stops. This was experimentally determined by extrapolating gas behavior. The 0.15 comes from more precise measurements than Celsius's original 0-100 scale based on water.

7. What's the hottest possible temperature?

Theoretically, there's no upper limit! The hottest temperature ever created on Earth was about 5.5 trillion°C (10 trillion°F) in particle accelerators. The Sun's core is 15 million°C (27 million°F).

8. How do animals handle extreme temperatures?

Arctic foxes survive -70°C (-94°F), while Pompeii worms live near hydrothermal vents at 80°C (176°F). Human survival range is much narrower: about -40°C to +40°C (-40°F to 104°F) without protection.

9. Why does wind make it feel colder?

Wind chill isn't actual temperature but "feels like" temperature. Wind removes the warm air layer around your body faster, making you lose heat more quickly. Our calculator doesn't calculate wind chill, but weather apps do.

10. How does altitude affect boiling point?

At higher altitudes, air pressure is lower, so water boils at lower temperatures. In Denver (1600m/5280ft), water boils at 95°C (203°F) instead of 100°C (212°F). This affects cooking times!

11. What's the difference between heat and temperature?

Temperature measures how hot something is (average molecular energy). Heat measures total thermal energy. A cup of boiling water (100°C) and a bathtub of warm water (40°C) - the cup has higher temperature but the bathtub has more heat energy.

12. Why do we use ° symbol for temperature?

The degree symbol (°) indicates a scale division. It comes from measuring angles (360° in a circle). Early thermometers were circular, so the same symbol was adopted for temperature scales.

13. How do digital thermometers work?

Most use thermistors (resistors that change with temperature) or thermocouples (two different metals that create voltage when heated). The change is measured and converted to digital readouts.

14. What's the best way to learn temperature conversions?

Memorize key points (freezing, body temp, boiling), use the mental tricks (double and add 30), and practice with real examples. Our converter helps by showing all scales at once!

15. Can temperature be negative in Kelvin?

No! 0K is absolute zero. However, in quantum physics, there are theoretical concepts of "negative temperature" that are actually hotter than any positive temperature - but that's advanced physics!

Final Tips and Tricks

• Remember these anchors: 0°C/32°F (freezing), 20°C/68°F (room), 37°C/98.6°F (body), 100°C/212°F (boiling)
• For cooking: Most oven conversions are: °C = (°F - 32) ÷ 1.8, rounded to nearest 5 or 10
• For weather: Under 10°C = coat weather, 10-20°C = sweater weather, over 20°C = t-shirt weather
• Quick check: If it's over 30°C, it's hot. If it's under 0°C, it's freezing.

Pro Conversion Tip

The best way to learn is to practice with temperatures you encounter daily. What's today's high in both scales? What temperature do you set your oven to? Practice makes perfect!