Enter a temperature and wind speed to calculate wind chill.
How to Use the Wind Chill Calculator
Enter a temperature and a wind speed, toggling each unit independently — °F/°C for temperature, mph/km/h for wind speed — since forecasts mix both conventions depending on where you're reading them. A note appears if wind speed drops below 3 mph or temperature climbs above 50°F, the two conditions where the formula stops applying.
What Wind Actually Does to Your Skin
Skin sits under a thin layer of air your body warms slightly through convection — a personal insulating bubble a few millimeters thick. Wind strips that layer away and replaces it with cold ambient air, over and over, faster than the body can rewarm a fresh layer. The stronger the wind, the more often that boundary gets refreshed with cold air, and the faster heat actually leaves the body — even though the air's real temperature hasn't dropped at all.
Wc = 35.74 + 0.6215T − 35.75(V^0.16) + 0.4275T(V^0.16)
T is temperature in °F, V is wind speed in mph.
A Formula With an Odd History
This is the 2001 North American wind chill formula, adopted jointly by the US National Weather Service and Environment Canada, replacing a version dating to 1945 with a strange pedigree: it came out of an Antarctic expedition where researchers measured how quickly plastic containers of water froze at different wind speeds. That's a model of an inanimate object losing heat, not a model of living skin — plastic doesn't sweat, doesn't redirect blood flow to conserve core temperature, and doesn't generate its own heat. The 2001 revision was built instead from actual human trials, which is why it's treated as a meaningfully more accurate model of how cold moving air really feels to a person, rather than how fast a container of water gives up its heat.
Below 3 mph, the formula isn't applied at all — wind that light doesn't meaningfully strip away the insulating air layer, so the calculator just shows the air temperature itself. Above 50°F, the formula still runs, but its output shouldn't be trusted; wind chill as a concept only really applies to cold-weather heat loss.