4 °F at a glance
- Celsius
- −15.56 °C
- Exact fraction
- −15 5/9 °C
- Kelvin
- 257.59 K
- Rankine
- 463.67 °R
- Rounded
- −16 °C
- Quick estimate
- −13 °C
How to convert 4 °F to Celsius
(4 − 32) × 5/9 = −28 × 5/9 = −140/9 = −15.56 °C
Subtract 32 first because the two scales put zero in different places, then multiply by 5/9 because a Fahrenheit degree is only 5/9 the size of a Celsius degree. −28 is not a multiple of 9, so the exact answer is the repeating decimal −15 5/9 °C.
Estimate it in your head
Subtract 30 and halve: (4 − 30) ÷ 2 = −13 °C. That is 2.6 degrees high, close enough to decide what to wear.
What 4 °F means in everyday life
- Freezers. Home freezers should hold 0 °F (−17.8 °C), so 4 °F is 4 degrees warmer than a properly set freezer — still cold enough to keep ice solid.
- Ice. At −15.56 °C, puddles, ponds and wet roads freeze. Rock salt melts ice well near 32 °F but works more and more slowly as pavement temperatures drop into the teens and below.
- Wind chill. With wind, 4 °F feels much colder:
| Wind | Feels like | In °C | Note |
|---|---|---|---|
| 10 mph | −11 °F | −24 °C | Cover exposed skin |
| 20 mph | −17 °F | −27 °C | Cover exposed skin |
| 30 mph | −20 °F | −29 °C | Frostbite possible in 30 min or less |
Temperatures near 4 °F
| Fahrenheit | Celsius | Kelvin |
|---|---|---|
| −1 °F | −18.33 °C | 254.82 K |
| 0 °F | −17.78 °C | 255.37 K |
| 1 °F | −17.22 °C | 255.93 K |
| 2 °F | −16.67 °C | 256.48 K |
| 3 °F | −16.11 °C | 257.04 K |
| 4 °F | −15.56 °C | 257.59 K |
| 5 °F | −15 °C | 258.15 K |
| 6 °F | −14.44 °C | 258.71 K |
| 7 °F | −13.89 °C | 259.26 K |
| 8 °F | −13.33 °C | 259.82 K |
| 9 °F | −12.78 °C | 260.37 K |
Going the other way: −16 °C in Fahrenheit is 3.2 °F.
Frequently asked questions
What is 4 °F in Celsius?
4 °F is −15.56 °C: subtract 32 (−28) and multiply by 5/9.
Is 4 °F hot or cold?
4 °F is below freezing — water turns to ice and roads can be slick.
How do you convert 4 °F to Celsius in your head?
Subtract 30 and divide by 2: (4 − 30) ÷ 2 = −13 °C, compared with the exact −15.56 °C.
What is 4 °F in Kelvin?
4 °F is 257.59 K. Convert to Celsius (−15.56 °C) and add 273.15.