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Temperature Converter

Convert between Celsius, Fahrenheit, Kelvin, and Rankine — the four temperature scales used in weather, cooking, scientific research, and engineering work.

Enter your values

Result

100°C =
212 °F
Quick answer

Temperature converts between Celsius (°C — used in India and most of the world), Fahrenheit (°F — US), Kelvin (K — science), and Rankine (°R — US engineering). Unlike most conversions, temperature uses an offset and a scale, not a single multiplier.

What is Temperature Converter?

Temperature is the only common unit conversion that involves an offset, not just a multiplier. Water freezes at 0°C and 32°F, so converting between the two scales requires shifting the zero point first, then applying the slope.

Celsius is the everyday scale in India and most of the world. Water freezes at 0, boils at 100. Body temperature is around 37. Indian summer hits the mid-40s in the north; mountain stations drop to single digits.

Fahrenheit is used in the US and a few other places. 32 is freezing, 212 is boiling, body temperature is 98.6, room temperature is around 70.

Kelvin is the scientific absolute scale. Zero Kelvin is absolute zero (−273.15°C) — the theoretical absence of all thermal energy. The scale slope is identical to Celsius — a 1 K change equals a 1°C change.

Temperature formulas

Formula
°C → °F: F = C × 9/5 + 32 °F → °C: C = (F − 32) × 5/9 °C → K: K = C + 273.15 K → °C: C = K − 273.15
C
Celsiustemperature in Celsius
F
Fahrenheittemperature in Fahrenheit
K
Kelvinabsolute temperature in Kelvin
Worked example
Value100°C
TargetFahrenheit
F = 100 × 9/5 + 32
F = 180 + 32
100°C = 212°F (boiling point of water)

How to use this calculator

Pick a source temperature scale, target scale, and enter a value.

  1. Enter the temperature value

    Decimal-precise, including negatives. Body temperature ≈ 37°C; freezing point of water = 0°C.

  2. Pick the source scale

    Celsius for daily Indian use, Fahrenheit for US contexts, Kelvin for scientific work.

  3. Pick the target scale

    Same set of options. The calculator handles the offset automatically.

Common temperature conversions

Body temperature

98.6°F (US standard) = 37°C. Fever above 100°F = 37.8°C.

Weather reports

Comparing news from US (Fahrenheit) with India (Celsius). 70°F = 21°C, comfortable spring.

Cooking

American recipes use °F for oven temperatures. 350°F = 177°C — a common baking temperature.

Air conditioning

Indian ACs default to 24°C; US thermostats to 72°F. Both about the same.

Scientific lab

Kelvin is preferred for absolute calculations. Room temperature ≈ 293 K.

Common mistakes to avoid

Doubling °C and adding 30 for a precise answer

That shortcut (40°C → ~110°F) is fine for weather talk but drifts up to 5°F off at extremes. The exact rule is ×1.8 + 32: 40°C = 104°F. Use the calculator when it's a fever reading or an oven setting.

Converting temperature DIFFERENCES with the +32 offset

A rise of 20°C is a rise of 36°F (×1.8 only — no +32). The offset applies to temperature points, not to changes between them.

Reading a US recipe's 350° as Celsius

American ovens are Fahrenheit: 350°F = 177°C ≈ the 180°C standard baking temperature. Setting an Indian oven to 350°C will incinerate the cake.

Glossary

Celsius (°C)
Water-based scale: 0 = freezing, 100 = boiling at standard atmospheric pressure.
Fahrenheit (°F)
Older scale used mainly in the US. 32 = freezing, 212 = boiling.
Kelvin (K)
SI absolute scale. 0 K = absolute zero. Used in science.
Absolute zero
−273.15°C — the theoretical lowest possible temperature, where molecular motion stops.

Frequently asked questions

How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32: °F = °C × 1.8 + 32. So 40°C — a hot Indian summer day — is 104°F. For a rough mental estimate, double the Celsius and add 30.
How do I convert Fahrenheit to Celsius?
Subtract 32 and multiply by 5/9: °C = (°F − 32) × 0.5556. A 98.6°F body temperature is exactly 37°C.
What is the Kelvin scale used for?
Kelvin is the SI unit for science and engineering. It starts at absolute zero (0 K = −273.15°C), the coldest possible temperature. Add 273.15 to any Celsius value to get Kelvin — 25°C = 298.15 K.
At what temperature are Celsius and Fahrenheit equal?
At −40 degrees. It's the single point where both scales read the same: −40°C = −40°F.
What is normal body temperature in Celsius and Fahrenheit?
Around 37°C (98.6°F), with a normal range of 36.1–37.2°C. A fever is generally 38°C (100.4°F) or above measured orally.
Disclaimer: Results are estimates based on the inputs you provide. They are not professional advice. For consequential decisions — financial, tax, medical, or legal — verify with a qualified professional.

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