Geography
Geography Calculators
Distance, bearings, density, wind chill, humidity, and elevation math.
10 tools
Atmospheric Pressure Calculator
Atmospheric pressure calculator: compute air pressure at any altitude using barometric formulas. Free, editable units, runs in your browser, no signup.
Bearing Calculator
Bearing calculator: initial compass bearing between two coordinates. Free bearing calculator with the formula shown - runs entirely in your browser, no signup.
Coordinate Converter
Coordinate converter: switch latitude and longitude between decimal degrees and degrees minutes seconds format. Free, private, runs locally, no signup needed.
Distance Between Coordinates Calculator
Distance between coordinates calculator: measure the miles or km between two GPS points using the haversine formula. Free, runs locally in your browser.
Geographic Area Calculator
Geographic area calculator: compute the area of any region from shape dimensions, coordinates or vertices. Free, runs locally in your browser, no signup.
Growing Degree Day Calculator
Growing degree day calculator: accumulate GDD for crops at any base temperature, plus heating and cooling degree days at 65F. Free, private, runs in your browser.
Humidity Index Calculator
Humidity index calculator: convert air temperature and relative humidity into the apparent heat index you actually feel outdoors. Free, private, no signup.
Population Density Calculator
Population density calculator: divide population by land area to get people per square mile or km instantly. Free, editable units, runs locally, no signup.
Wet Bulb Temperature Calculator
Wet bulb temperature calculator: compute wet bulb from air temperature, humidity and pressure, with heat stress risk levels. Free, runs in your browser.
Wind Chill Calculator
Wind chill calculator: convert air temperature and wind speed into how cold it actually feels on exposed skin outdoors. Free, private, runs in your browser.
How these geography tools work
Every calculation here uses a published formula: great-circle distance via the haversine formula on a spherical earth, population density as count divided by land area, wind chill from the National Weather Service formulation, and heat index from the NWS regression.
The earth-is-a-sphere assumption introduces up to about 0.5 percent distance error versus an ellipsoid model; for city-to-city planning that is negligible, and each page says so.
Choosing a tool
Distance and bearing questions use the haversine tools, demographic questions use population density, and weather-comfort questions use wind chill or heat index. ZIP-code tools resolve lookup questions (which county, which timezone) rather than computing anything.
Honest limits
Weather comfort indices are calibrated to shade conditions and specific height measurements; they are screening values, not forecasts. Population densities are only as current as the census or estimate year the input data uses.