30 degrees Fahrenheit is equal to approximately -1.1111 degrees Celsius.
To convert 30 Fahrenheit to Celsius, you subtract 32 from the Fahrenheit value, then multiply the result by 5 divided by 9. This adjusts the temperature from the Fahrenheit scale, which uses the freezing point of water at 32, to the Celsius scale, which uses 0 as freezing.
Conversion Tool
Result in celsius:
Conversion Formula
The formula to convert Fahrenheit (°F) to Celsius (°C) is:
Celsius = (Fahrenheit – 32) × 5/9
This works because the Fahrenheit scale sets water freezing at 32°F and boiling at 212°F, while Celsius sets freezing at 0°C and boiling at 100°C. The difference between freezing and boiling points in Fahrenheit is 180 degrees, and in Celsius, 100 degrees. By subtracting 32, you align the zero points, then multiply by 5/9 to scale the ranges.
For example, converting 30°F to Celsius step-by-step:
- Subtract 32 from 30: 30 – 32 = -2
- Multiply by 5/9: -2 × 5/9 = -10/9 ≈ -1.1111
- So, 30°F ≈ -1.1111°C
Conversion Example
- Convert 50°F to Celsius:
- Subtract 32: 50 – 32 = 18
- Multiply by 5/9: 18 × 5/9 = 90/9 = 10
- Answer: 50°F = 10°C
- Convert 70°F to Celsius:
- Subtract 32: 70 – 32 = 38
- Multiply by 5/9: 38 × 5/9 ≈ 21.1111
- Answer: 70°F ≈ 21.1111°C
- Convert 15°F to Celsius:
- Subtract 32: 15 – 32 = -17
- Multiply by 5/9: -17 × 5/9 ≈ -9.4444
- Answer: 15°F ≈ -9.4444°C
- Convert 100°F to Celsius:
- Subtract 32: 100 – 32 = 68
- Multiply by 5/9: 68 × 5/9 ≈ 37.7778
- Answer: 100°F ≈ 37.7778°C
Conversion Chart
| Fahrenheit (°F) | Celsius (°C) |
|---|---|
| 5.0 | -15.0000 |
| 10.0 | -12.2222 |
| 15.0 | -9.4444 |
| 20.0 | -6.6667 |
| 25.0 | -3.8889 |
| 30.0 | -1.1111 |
| 35.0 | 1.6667 |
| 40.0 | 4.4444 |
| 45.0 | 7.2222 |
| 50.0 | 10.0000 |
| 55.0 | 12.7778 |
This chart shows Fahrenheit values in the left column, and their Celsius equivalents on the right. To find a Celsius temperature, locate the Fahrenheit value and check the corresponding Celsius number. It’s quick for rough conversions without calculations.
Related Conversion Questions
- How cold is 30 degrees Fahrenheit in Celsius?
- What’s the Celsius equivalent of 30°F for weather forecasts?
- Is 30°F above or below freezing in Celsius?
- How do I convert 30°F to Celsius without a calculator?
- What temperature in Celsius matches 30 degrees Fahrenheit?
- Does 30°F equal zero Celsius or less?
- How much colder in Celsius is 30°F compared to 40°F?
Conversion Definitions
Fahrenheit: Fahrenheit is a temperature scale used primarily in the United States, based on 32°F as the freezing point of water and 212°F as the boiling point. The scale divides this range into 180 equal parts. It was developed by Daniel Gabriel Fahrenheit in the 18th century.
Celsius: Celsius is a temperature scale used widely worldwide, defined by 0°C as the freezing point of water and 100°C as boiling point under standard atmospheric pressure. The scale divides the interval into 100 equal parts, making it part of the metric system.
Conversion FAQs
Why do we subtract 32 when converting Fahrenheit to Celsius?
The subtraction of 32 aligns the Fahrenheit temperature to the Celsius zero point. Since 32°F is where water freezes, subtracting 32 shifts the scale down so that zero corresponds to freezing in Celsius. Without subtracting 32, the conversion would be inaccurate.
Can I convert Fahrenheit to Celsius by just multiplying by 0.5?
Multiplying by 0.5 is a rough shortcut but not precise. Since the Fahrenheit scale has a different zero point and a larger range between freezing and boiling points, the formula (F – 32) × 5/9 gives an exact conversion. Using only multiplication ignores the offset.
Does converting -40°F give the same Celsius value?
Yes, -40°F equals -40°C. This is the unique point where both temperature scales intersect. The formula confirms this: (-40 – 32) × 5/9 = -72 × 5/9 = -40°C exactly.
Is the conversion different for temperatures below zero?
The formula remains the same regardless of temperature. Whether the Fahrenheit value is positive or negative, subtract 32 then multiply by 5/9 to get Celsius. Negative Fahrenheit temperatures convert to negative Celsius values following the same steps.
Why does 30°F convert to a negative Celsius value?
Because 30°F is below the freezing point of water, which is 0°C, the converted Celsius temperature is negative. When you subtract 32 from 30, you get a negative number, leading to a negative Celsius value after multiplying by 5/9.