Fahrenheit to Celsius
Fahrenheit to Celsius, updated live. °C = (°F − 32) × 5/9, so 98.6°F (normal body temperature) is 37°C — type any value and the result follows along.
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Oven temperature reference
| Gas mark | Fahrenheit (°F) | Celsius (°C) | Heat |
|---|---|---|---|
| 1 | 275 | 135 | Slow |
| 2 | 300 | 150 | Slow |
| 3 | 325 | 165 | Moderately slow |
| 4 | 350 | 180 | Moderate |
| 5 | 375 | 190 | Moderate |
| 6 | 400 | 205 | Moderately hot |
| 7 | 425 | 220 | Hot |
| 8 | 450 | 230 | Hot |
| 9 | 475 | 245 | Very hot |
How to use
- Type a value and pick the units to convert from and to. Comma-grouped and full-width digits are accepted.
- Press the swap button to flip the two units instantly.
- Check the oven temperature table below for the gas-mark equivalent of any recipe temperature.
- If the result would be colder than absolute zero, a warning appears — that temperature is not physically possible.
The three formulas
Celsius to Fahrenheit: °F = °C × 9/5 + 32. Fahrenheit to Celsius: °C = (°F − 32) × 5/9. Celsius to Kelvin: K = °C + 273.15 (Kelvin has no negative values — 0 K, or -273.15°C, is absolute zero, the coldest anything can get). The scales agree at exactly one point: -40°C equals -40°F. This converter uses the formulas above rather than rounded shortcuts. Very small and very large finite results use scientific notation so a nonzero value is never shown as zero.
Oven temperatures and gas mark
UK and Irish gas ovens are marked with a "gas mark" number instead of a temperature. Gas mark 4 (350°F / 180°C) is the most common "moderate" baking temperature; gas mark 7 (425°F / 220°C) is a hot oven for roasting. These are the rounded values recipes actually print — not the exact math conversion. For example, 350°F converts mathematically to about 176.7°C, but recipes and oven dials use 180°C instead, because home ovens are rarely accurate to better than ±5°C anyway. The table below lists gas marks 1 through 9 with both the Fahrenheit and Celsius values printed on real recipes and oven dials.
Frequently asked questions
What is 350°F in Celsius for baking?
For an oven, 350°F is treated as 180°C (gas mark 4) — the standard rounded recipe equivalent, not the exact math conversion of about 176.7°C. Use 180°C on the dial; home ovens are not accurate enough for the extra few degrees to matter.
How do you convert Celsius to Fahrenheit?
Multiply the Celsius value by 9/5 and add 32: °F = °C × 9/5 + 32. For example, 20°C × 9/5 = 36, plus 32 = 68°F.
How do you convert Fahrenheit to Celsius?
Subtract 32, then multiply by 5/9: °C = (°F − 32) × 5/9. For example, (98.6 − 32) × 5/9 = 37°C, normal human body temperature.
What temperature is the same in Celsius and Fahrenheit?
-40 degrees. -40°C equals exactly -40°F — the one point where both scales give the same number.
What is 0 Kelvin in Celsius and Fahrenheit?
0 K is -273.15°C (-459.67°F), known as absolute zero — the theoretical lower limit of temperature, where nothing can be colder. Kelvin values below 0 are not physically possible.
What gas mark is 220°C?
220°C is gas mark 7 (425°F), described as a "hot" oven — common for roasting vegetables or baking bread.
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Updated 2026-10-19