Free engineering calculators and unit convertersceo@instrumentationblog.in
Common Converters · Free Online Tool

Temperature Converter

Convert between 5 temperature units instantly. Enter a value, pick your units and get the result with the formula, a full conversion table and worked examples.

°C°FK°R°Ré+0 more
100 °C = 212 °F
Formula: °F = °C × 1.8 + 32
Popular:

100 °C in all temperature units

Updates live as you type. Click a row to set it as the target unit.

UnitSymbolValue
Celsius°C100
Fahrenheit°F212
KelvinK373.15
Rankine°R671.67
Réaumur°Ré80
Advertisement

How to Convert Temperature Units

Temperature describes how hot or cold a body is. The SI unit is the kelvin (K); Celsius and Fahrenheit scales are offset from it, so conversions need both a scale factor and an offset, not a single multiplier.

Every temperature scale is converted through kelvin. First turn the input into kelvin, then turn kelvin into the target scale. The common direct formulas are:

°F = °C × 1.8 + 32
°C = (°F − 32) ÷ 1.8
K = °C + 273.15
°R = °F + 459.67
Worked example: convert 100 celsius to fahrenheit. Using °F = °C × 1.8 + 32: 100 × 1.8 + 32 = 212 °F.

Celsius to Fahrenheit conversion table

Celsius (°C)Fahrenheit (°F)
−40 °C−40 °F
−30 °C−22 °F
−20 °C−4 °F
−10 °C14 °F
0 °C32 °F
5 °C41 °F
10 °C50 °F
15 °C59 °F
20 °C68 °F
25 °C77 °F
30 °C86 °F
35 °C95 °F
37 °C98.6 °F
40 °C104 °F
50 °C122 °F
60 °C140 °F
70 °C158 °F
80 °C176 °F
90 °C194 °F
100 °C212 °F
150 °C302 °F
200 °C392 °F
250 °C482 °F
300 °C572 °F
500 °C932 °F
1,000 °C1,832 °F

Temperature Units and Conversion Factors

Formula to convert each scale into kelvin.

UnitSymbolTo kelvin
Celsius°CK = °C + 273.15
Fahrenheit°FK = °F × 0.55555556 + 255.37222
KelvinKK = K × 1
Rankine°RK = °R × 0.55555556
Réaumur°RéK = °Ré × 1.25 + 273.15
Advertisement

Frequently Asked Questions

What is the SI unit of temperature?

The SI unit of temperature is the kelvin (K). Temperature describes how hot or cold a body is.

How do I convert °C to °F?

To convert celsius (°C) to fahrenheit (°F), use the formula °F = °C × 1.8 + 32. For example, 1 °C = 33.8 °F.

How do I convert °F to °C?

To convert fahrenheit (°F) to celsius (°C), use the formula °C = °F × 0.555556 − 17.7778. For example, 1 °F = −17.2222 °C.

How do I convert °C to kelvin?

To convert celsius (°C) to kelvin (K), use the formula K = °C + 273.15. For example, 1 °C = 274.15 K.

Why is temperature conversion not a simple multiplication?

Celsius and Fahrenheit have different zero points as well as different degree sizes. You must apply both a scale factor and an offset; only kelvin and Rankine start at absolute zero. For temperature differences, use the temperature interval converter instead.

Can I see a value in every temperature unit at once?

Yes. Enter a value and choose the source unit; the "all units" table below the converter instantly lists the equivalent in all 5 supported units. Click any row to make it the target unit.

You May Also Like

Learn the theory behind it

Thermocouple and RTD installation precautions

A practical, field focused guide on instrumentationblog.in that explains where these units come from and how engineers use them on real plants.

Read Full Article

More Common Converters

Popular Engineering Converters

Frequently used tools from our full library of 76 unit converters.

Browse all unit converters →