Celsius to Fahrenheit Converter

Instant, two-way conversion across common engineering units.

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1 °C = 33.8 °F(CelsiusFahrenheit)

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Converting Celsius to Fahrenheit

To convert Celsius to Fahrenheit, multiply the value by 9/5 and add 32. Temperature scales use offsets as well as ratios, so a conversion formula is applied rather than a single multiplier.

Visual scale

Equivalent temperature
100 °C = 212 °F.
0 °C = 32 °F.

Temperature scales have different zero points, so the values are matched at the same physical temperature rather than compared by size.

Celsius (°C)

Celsius (°C) is the everyday temperature scale used in most of the world and in building physics.

Origin
Based on the freezing and boiling points of water at standard pressure, and now defined from the kelvin.
Where it is used
Used for design temperatures, thermal comfort, concrete curing and HVAC setpoints.
Relation to SI
0 °C = 273.15 K. A Celsius degree is the same size as a kelvin.

Fahrenheit (°F)

Fahrenheit (°F) is the temperature scale used in the United States.

Origin
Devised by Daniel Gabriel Fahrenheit in 1724; water freezes at 32 °F and boils at 212 °F.
Where it is used
Used in US weather data, HVAC design and building codes.
Relation to SI
°F = °C x 9/5 + 32, so 0 °C is 32 °F.

Frequently asked questions

How do I convert Celsius to Fahrenheit?

To convert Celsius to Fahrenheit, multiply the value by 9/5 and add 32. For example, 20 °C equals 68 °F.

How do I convert back from Fahrenheit to Celsius?

Reverse the formula: subtract 32 from the value, then multiply by 5/9. The converter above works in both directions, so you can type into either field.

Why does temperature conversion use formulas instead of ratios?

Celsius and Fahrenheit have different zero points, so a simple multiplier cannot work. Each conversion applies both a scale factor and an offset.

How do Celsius and Fahrenheit differ?

Water freezes at 0 °C or 32 °F and boils at 100 °C or 212 °F, so one Celsius degree covers 1.8 Fahrenheit degrees. The scales cross at -40.

When should I use kelvin?

Kelvin is the SI unit and starts at absolute zero, so it is used for thermal calculations, U-values and any scientific reporting. Temperature differences are identical in kelvin and Celsius.

Is this temperature converter free to use?

Yes. Every unit conversion runs in your browser, needs no account and is free for professional use.

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