Wind Chill Calculator
Quickly find your Wind chill temp with our free Wind Chill Calculator. Simple, fast, and accurate.
Conditions
Wind chill
What is a Wind Chill Calculator?
A wind chill calculator tells you how cold it really feels outside by accounting for the effect of wind on skin temperature. The actual air temperature might be 30°F, but a 20 mph wind makes it feel much colder. This is critical for planning outdoor activities, dressing appropriately in winter, and avoiding cold-related injuries like frostbite and hypothermia.
How wind chill is calculated (the formula)
The National Weather Service wind chill formula (adopted in 2001) is:
Wind Chill = 35.74 + 0.6215(T) - 35.75(V0.16) + 0.4275(T)(V0.16)
Where:
T = air temperature in degrees Fahrenheit
V = wind speed in miles per hour
The formula applies only when the air temperature is at or below 50°F and wind speed is above 3 mph. For conditions using Celsius and km/h, the calculator converts your inputs before applying the formula.
Example calculation
The air temperature is 20°F with a wind speed of 15 mph. Is it colder than it looks?
Step 1: T = 20, V = 15
Step 2: V0.16 = 150.16 = 1.542
Step 3: 0.6215 × 20 = 12.43
Step 4: 35.75 × 1.542 = 55.13
Step 5: 0.4275 × 20 × 1.542 = 13.19
Step 6: 35.74 + 12.43 - 55.13 + 13.19 = 6.2°F
A 20°F day with 15 mph wind feels like 6°F. Frostbite can develop on exposed skin in about 30 minutes at this level.
Common mistakes
- Applying wind chill above 50°F — the formula was designed for cold conditions only. Above 50°F the wind chill effect is minimal and the calculation is meaningless.
- Using wind chill for objects or pipes — wind chill only affects living things. A pipe at 20°F stays at 20°F regardless of wind, though wind may help it reach that temperature faster.
- Mixing units — using temperature in Celsius with wind speed in mph (or vice versa) produces gibberish. The calculator handles this automatically, but manual calculation requires consistent units.
- Confusing wind chill with actual temperature — wind chill is how fast your body loses heat, not a change in actual air temperature. The thermometers still read the same number.
- Forgetting the 3 mph lower bound — below 3 mph wind speed, the formula breaks down. Very light wind has negligible cooling effect beyond the ambient air itself.
Frequently asked questions
How is wind chill calculated?
The standard wind chill formula used by meteorologists is: Wind Chill = 35.74 + 0.6215T - 35.75V0.16 + 0.4275TV0.16, where T is air temperature in Fahrenheit and V is wind speed in mph. This formula applies when the temperature is at or below 50°F and wind speed is above 3 mph.
What formula do meteorologists use for wind chill?
Meteorologists in the US use the NWS wind chill formula adopted in 2001: Wind Chill = 35.74 + 0.6215T - 35.75(V0.16) + 0.4275T(V0.16). It was developed through human testing in a wind tunnel and is used when the temperature is at or below 50°F with wind speeds above 3 mph.
Why does wind make the temperature feel colder?
Wind removes the thin layer of warm air that naturally surrounds your skin. When that insulating layer is carried away faster, your body loses heat more quickly through convection. The stronger the wind, the faster the heat loss, and the colder you feel even though the actual air temperature has not changed.
At what wind chill does frostbite occur?
Frostbite can occur on exposed skin in under 30 minutes when the wind chill is at or below -18°F (-28°C). At -40°F wind chill, frostbite can set in within 5-10 minutes. Always check wind chill before spending extended time outdoors in cold, windy conditions.
Does wind chill affect inanimate objects?
No. Wind chill only affects living things because it measures how fast heat is lost from a warm body. A car radiator or a water pipe will not cool below the actual air temperature regardless of wind speed. However, wind can help objects reach ambient temperature faster.
Why is there no wind chill above 50°F?
The standard wind chill formula was designed and tested for cold conditions. Above 50°F, the cooling effect of wind is much smaller and the formula is not accurate. Instead, the heat index is used to measure how hot it feels in warm weather.