Wind Chill Calculator

What this calculator does

The Wind Chill Calculator estimates how cold the air feels on exposed skin when wind is combined with low air temperature. It uses the National Weather Service (NWS) wind chill formula, which is based on human heat loss in cold, windy conditions.

Wind chill is not a measured temperature. The actual air temperature does not change when the wind blows; the wind increases heat loss from exposed skin, so the air feels colder. The result is reported in Fahrenheit, Celsius, and Kelvin.

How to use this calculator

1. Enter the air temperature.
2. Choose Fahrenheit, Celsius, or Kelvin.
3. Enter the wind speed and choose miles per hour, kilometers per hour, meters per second, or knots.
4. Click Calculate.

The default example uses 10 °F and 15 mph. The NWS formula gives a wind chill of about −6.6 °F, which is commonly rounded to −7 °F. The result card also shows the Celsius and Kelvin equivalents and whether the inputs fall inside the formula's valid range.

Wind chill formula

Wind chill (°F) =
  35.74
  + 0.6215T
  − 35.75V^0.16
  + 0.4275T × V^0.16

T = air temperature in °F
V = wind speed in mph

For Celsius or Kelvin input, the calculator converts the temperature to Fahrenheit first. For kilometers per hour, meters per second, or knots, it converts the wind speed to miles per hour before applying the formula. The Celsius result is then obtained by converting the Fahrenheit wind chill back.

What the results mean

A lower wind chill means exposed skin loses heat faster. The NWS formula is defined for air temperatures at or below 50 °F and wind speeds of at least 3 mph. Outside that range, the calculator still produces a number but labels it as an extrapolation.

Wind chill describes heat loss from exposed skin, not the temperature of objects. A car engine or a pipe does not cool to the wind chill value, although wind can speed up cooling toward the actual air temperature. Frostbite risk rises quickly when the wind chill is far below freezing.

Assumptions and limitations

• The formula assumes a person walking into the wind at about 3 mph, standard clothing, and no strong sun.
• It applies to exposed skin, not to skin covered by clothing.
• The result is an estimate of perceived cold, not a medical assessment of frostbite or hypothermia risk.
• Strong sun, altitude, humidity, and individual health can change how cold a person feels.
• The calculator does not model heat loss in watts or provide a frostbite time. Those outputs are outside its scope.
• This is a screening and planning tool, not medical advice.

Frequently asked questions

Does wind chill change the actual temperature?

No. The thermometer still reads the air temperature. Wind chill is an estimate of how that temperature feels on exposed skin because moving air carries heat away faster.

Why is the formula limited to 50 °F and 3 mph?

The NWS formula was developed and validated for cold, windy conditions. At very low wind speeds or mild temperatures, the formula becomes less meaningful, so the calculator marks the result as an extrapolation.

Can I enter Celsius and kilometers per hour?

Yes. Choose the matching units and the calculator converts them before applying the NWS formula. The result is shown in both Fahrenheit and Celsius.

Reference table

Wind speed units

The NWS wind chill formula applies at temperatures at or below 50 °F and wind speeds of at least 3 mph. Outside that range the result is an extrapolation.

Source

Reference: Calculator.net — Wind Chill Calculator. Formula source: National Weather Service wind chill chart and equation.

Disclaimer

This calculator provides an estimate for planning and is not medical advice. Cold weather can cause frostbite and hypothermia. Follow local weather warnings and seek shelter if you experience numbness, confusion, or uncontrolled shivering.