0 Fahrenheit to Celsius
-17.8 °C
0 °F = -17.8 °C.
Celsius
-17.8°C
0 °F = -17.8 °C
The short answer
How many Celsius is 0 Fahrenheit?
0 °F = -17.8 °C. 1 Fahrenheit = 0.555556 Celsius, then − 17.77777777777778, so the working is 0 × 0.555556 − 17.7778 = -17.8.
The working
The factor below is an exact definition rather than a measurement, so nothing is approximated in the arithmetic. The only rounding on this page happens where a number is displayed.
1 Fahrenheit = 0.555556 Celsius, then − 17.77777777777778 0 × 0.555556 − 17.7778 = -17.8
How much precision do you need?
Each row is the same answer cut at a different number of decimals, with what that choice costs you. Pick the shortest row whose error is smaller than whatever you are measuring with.
| Rounded to | Answer (°C) | Off by |
|---|---|---|
| Whole number | -18 | −0.22222 |
| 1 decimal | -17.8 | −0.02222 |
| 2 decimals | -17.78 | −0.00222 |
Round trip: take -17.8 °C back the other way and you land on -0.0400 °F — a drift of 0.0400 °F. That gap is the rounding, not the conversion.
What 0 °F looks like
0 °F
Zero Fahrenheit, which is -18 Celsius, is the freezer temperature the FDA recommends for keeping frozen food indefinitely safe.
Frequently asked questions
What is 0 Fahrenheit in Celsius?
0 Fahrenheit is -17.8 Celsius. 1 Fahrenheit = 0.555556 Celsius, then − 17.77777777777778, so the working is 0 × 0.555556 − 17.7778 = -17.8.
How accurate is -17.8 °C?
Rounding to -17.8 °C and converting straight back gives -0.0400 °F, a drift of 0.0400 °F from the 0 you started with. The factor itself is exact; every bit of that difference comes from the rounding, not the conversion.
Nearby values
Any value at all
Fahrenheit to Celsius Converter
Convert Fahrenheit to Celsius — fevers, recipes, and forecasts abroad.
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