Wind Chill Calculator
This wind chill calculator tells you how cold it really feels once the wind is factored in, using the official National Weather Service formula. Enter the air temperature and the wind speed, in either Fahrenheit and mph or Celsius and km/h, and you'll get the feels-like temperature plus the frostbite risk for those conditions. It's the number that matters when you're deciding how to dress for the cold, since the wind can make a big difference.
- Official NWS formula
- °F or °C
- Feels-like temp
- Frostbite risk
- Live thermometer
Last updated June 18, 2026 Method: NWS wind chill formula Reviewed by the Calcowa weather team
Low risk
WC = 35.74 + 0.6215T − 35.75V^0.16 + 0.4275T·V^0.16
How is wind chill calculated?
Wind chill comes from the National Weather Service formula: WC = 35.74 + 0.6215T − 35.75V^0.16 + 0.4275T × V^0.16, where T is the air temperature in °F and V is the wind speed in mph. At 20°F with a 15 mph wind, it feels like about 6°F, a 14-degree drop.
The wind speed's raised to the 0.16 power, which is the formula's way of saying the extra cooling tapers off as the wind picks up. Going from calm to a stiff breeze makes a big difference, but doubling an already-strong wind adds far less. The formula applies at or below 50°F with winds above 3 mph, since that's where the wind genuinely changes how cold it feels. Above that, you won't notice it.
Finding the wind chill step by step
You only need two readings, and you've probably got both already. Here's how the calculator turns them into a feels-like number:
- 1
Get the air temperatureRead it from a thermometer or a forecast, in °F or °C.
- 2
Get the wind speedUse the sustained wind, not a gust, in mph or km/h.
- 3
Check the limitsWind chill applies at or below 50°F and winds above 3 mph.
- 4
Apply the NWS formulaPlug both into the equation, raising the wind to the 0.16 power.
- 5
Read the riskCompare the feels-like number to the frostbite guide so you'll know how to dress.
Wind chill and frostbite risk
The colder the wind chill, the faster exposed skin freezes. Down around -18°F, frostbite starts within 30 minutes, and below roughly -35°F it'll happen in 10 minutes or less. That's why the National Weather Service issues wind chill advisories and warnings, and why covering every patch of skin matters on the worst days. This is the cold-weather twin of the Heat Index Calculator, which shows how hot it feels in summer, and it pairs with the Dew Point Calculator for a fuller read on the air.
Wind chill at a glance
A few worked combinations so you can see how fast it drops. Colder air and stronger wind both deepen the chill, and the frostbite window shrinks with it.
| Temp and wind | Feels like | Good to know |
|---|---|---|
| 40°F, 10 mph | 34°F | Cool, no real risk |
| 20°F, 15 mph | 6°F | Cold, bundle up |
| 0°F, 20 mph | -22°F | Frostbite possible in 30 min |
| -10°F, 25 mph | -37°F | Frostbite in 10 to 30 min |
| -20°F, 35 mph | -53°F | Frostbite in under 10 min |
Frequently asked questions
Is wind chill the same as feels-like temperature?
Mostly, in cold weather. The feels-like figure on a forecast is the wind chill when it's cold and the heat index when it's hot, so they're two halves of the same idea. Both translate the raw temperature into what your body actually senses, just for opposite ends of the thermometer.
Wind chill is how cold the air feels on exposed skin once you factor in the wind. Moving air strips away the thin warm layer your body builds up, so it pulls heat away faster and feels colder than the thermometer reads. It's why a breezy 20°F day can feel closer to 5°F, and it only matters at temperatures at or below 50°F.
The US National Weather Service formula is WC = 35.74 + 0.6215T − 35.75V^0.16 + 0.4275T × V^0.16, where T is the air temperature in °F and V is the wind speed in mph. The metric version uses °C and km/h with different constants. This calculator runs the official formula and handles both unit systems for you.
It takes the air temperature and the wind speed and combines them in the NWS equation, which raises the wind speed to the 0.16 power to capture how the cooling effect levels off at higher speeds. The formula applies for temperatures at or below 50°F and winds above 3 mph. Below that, wind chill isn't really meaningful, so the calculator notes it.
No, and that's a common mix-up. Wind chill only describes how cold it feels to living things that generate heat, like people and animals. Your car engine, water pipes, and a glass of water will only cool down to the actual air temperature, no matter how hard the wind blows. Wind can speed up how fast they reach that temperature, but it can't push them below it.
Frostbite risk climbs sharply as wind chill drops. Around -18°F it can set in within 30 minutes on exposed skin, and below about -35°F it can happen in 10 minutes or less. The calculator flags the risk level for your numbers, but treat it as a guide and cover up, since wind chill warnings are issued for good reason.
The formula kicks in at or below 50°F (10°C) with a wind above 3 mph. Above 50°F the wind doesn't make you feel meaningfully colder, so there's no wind chill to report. On the hot side, the opposite measure is the heat index, which adds humidity to show how much warmer it feels.
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Dew point calculatorWhen moisture and fog form.
Temperature converterCelsius, Fahrenheit, and Kelvin.
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