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Celsius to Fahrenheit Converter

Convert Celsius to Fahrenheit instantly, and edit either side to convert back.

Precision
Result
Fahrenheit
68.00°F
Kelvin
293.15K
Rankine
527.67°R
Common temperatures
Reference°C°FK
Absolute zero-273.15-459.670
Freezing point of water032273.15
Cold winter day-1014263.15
Room temperature2068293.15
Body temperature3798.6310.15
Hot summer day40104313.15
Boiling point of water100212373.15

How to convert Celsius to Fahrenheit

  1. Enter a temperature

    Type a value into the Celsius box to convert it to Fahrenheit.

  2. Or edit the Fahrenheit box

    Type into the Fahrenheit box to convert the other direction back to Celsius.

  3. Set precision

    Choose how many decimal places the results round to, from whole numbers to four decimals.

  4. Copy the result

    Copy the converted value or read Kelvin and Rankine alongside it.

Why use this tool

Two-way field

Edit Celsius or Fahrenheit and the other side updates live using F = C times 9/5 plus 32.

Kelvin and Rankine

Every conversion also shows the absolute Kelvin and Rankine scales for science and engineering work.

Adjustable precision

Round to whole numbers or up to four decimal places without losing accuracy in the underlying math.

Absolute-zero floor

Values below absolute zero are flagged, so you never get a physically impossible reading.

Reference table

A table of common temperatures from freezing to body heat to boiling gives instant context.

Private by design

Every conversion runs on your device. Nothing you type is uploaded or stored.

About this tool

This Celsius to Fahrenheit converter turns any temperature into its Fahrenheit equivalent the moment you type it. The formula is simple: Fahrenheit equals Celsius multiplied by nine fifths, then add thirty-two. Reverse it and Celsius equals Fahrenheit minus thirty-two, multiplied by five ninths. Because the field is two-way, you can edit either box and read the answer on the other side without switching modes.

Alongside the two everyday scales, the tool shows Kelvin and Rankine. Kelvin shares the size of a Celsius degree but starts at absolute zero, the coldest temperature possible, at minus 273.15 Celsius. Rankine does the same for the Fahrenheit degree, starting at absolute zero as well. These absolute scales matter in physics, chemistry, and thermodynamics, so having all four in one view saves a second lookup.

Precision is yours to set. Round to whole degrees for a quick read of the weather, or keep up to four decimals for lab work and calibration. If you enter a value colder than absolute zero, the tool flags it rather than pretending it is valid, since no real temperature can go below that floor.

Need other units? Try the Speed converter, Area converter, or the general-purpose Unit converter for length, mass, and more.

Frequently asked questions

What is the formula for Celsius to Fahrenheit?
Multiply the Celsius value by nine fifths (1.8) and add thirty-two. For example, 20 Celsius becomes 68 Fahrenheit. To go back, subtract thirty-two and multiply by five ninths.
Can I convert Fahrenheit back to Celsius?
Yes. The field is two-way, so type a value into the Fahrenheit box and the Celsius box updates automatically. You can work in either direction at any time.
Why does it also show Kelvin and Rankine?
Kelvin and Rankine are absolute scales that start at absolute zero, which is useful for science and engineering. Showing all four scales saves you from a second conversion.
What happens if I enter a temperature below absolute zero?
The tool flags any value colder than minus 273.15 Celsius, because no real temperature can drop below absolute zero. You still see the math, but with a clear warning.
Is my data private?
Yes. Every conversion happens on your device as you type. Nothing you enter is uploaded, logged, or stored anywhere.

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