Convert Fahrenheit to Celsius.

About this conversion

Fahrenheit-to-Celsius: (°F − 32) × 5/9. This is the most-searched temperature conversion because Americans need to interpret European weather, oven settings, and medical thermometers — and vice versa.

Formula

°C = (°F − 32) × 5/9

Real-world examples

Reference values

Tips & tricks

• Mental shortcut: subtract 30 and divide by 2 for a rough °F → °C. 80 °F → (80-30)/2 = 25 °C (actual 26.7).
• For oven temperatures: 350 °F ≈ 175 °C; 400 °F ≈ 200 °C; 425 °F ≈ 220 °C. These are the standard baking conversions.
• The two scales cross at -40 (both °F and °C are -40 there). This is occasionally useful as a sanity-check.

Origin & history

The Fahrenheit scale was proposed by Daniel Fahrenheit in 1724. The Celsius scale was proposed by Anders Celsius in 1742, originally inverted (water freezes at 100°, boils at 0°) — flipped within a few years. Today the US, the Bahamas, the Cayman Islands, Liberia, and Belize use Fahrenheit for everyday weather; everyone else uses Celsius.

What is a degree Fahrenheit?

On the Fahrenheit scale, water freezes at 32°F and boils at 212°F — a 180-degree span vs Celsius's 100. Weather and everyday temperatures in the US and a few Caribbean territories.

What is a degree Celsius?

The Celsius scale is anchored to the freezing (0°C) and boiling (100°C) points of water at standard atmospheric pressure. Weather, cooking, and everyday temperatures in almost every country.

Real-world examples of °F

Some everyday comparisons can make the unit easier to picture.

• 98.6 °F — human body temperature.
• 212 °F — boiling point of water at sea level.
• 32 °F — freezing point of water.

How to convert degree Fahrenheit to degree Celsius

To convert a value from degree Fahrenheit (°F) to degree Celsius (°C), apply the conversion factor shown in the formula above. The calculation is the same whether you do it by hand, in a spreadsheet, or with the live converter on this page.

Steps:

1. Take your input value in °F.
2. Apply the formula see formula above.
3. The result is your value in °C.

For repeated calculations, save the formula in a spreadsheet or use the live converter at the top of this page — it handles the math automatically and displays the result as you type.

Frequently asked questions

How do I convert °F to °C?

Apply the formula °F → °C shown above, or just type your value into the converter at the top of this page. The result updates instantly.

Which is bigger, °F or °C?

This depends on the conversion ratio in the formula. If the factor multiplied by your value gives a larger number, then °C is the smaller unit (so it takes more of them to express the same quantity). If the result is smaller, then °C is the larger unit.

When would I use °F versus °C?

Both units measure temperature, so the choice depends on context. Degree fahrenheit is typically used for weather, cooking, science, and engineering; degree Celsius similarly. Most professional fields standardize on one or the other based on regional conventions or technical tradition.

How precise is this °F to °C conversion?

The conversion factor shown is the internationally defined exact value (or the best-published approximation if the relationship is irrational, like degrees-to-radians). The live converter on this page uses double-precision floating-point math, accurate to about 15 significant digits — far beyond any practical engineering need.

Is the conversion ratio exact, or an approximation?

Most unit conversions between SI metric units, and between SI and US customary units, have been formally defined as exact values since the 1959 international yard-pound agreement and subsequent SI redefinitions. Exceptions are unit pairs that involve irrational numbers (radians, e.g.) or empirical conversions (like food calories, which depend on temperature). When in doubt, consult the formula at the top of this page.

Related conversions

See also