Sun Exposure Seat Finder

The Bus Sun Side Calculator (also known as the Sun Exposure Seat Finder) is a high-precision, privacy-first tool designed to help you determine exactly which side of the bus to sit to avoid direct solar rays. Rather than guessing or manual estimation, our calculator implements exact geodesic bearing algorithms and astronomical formulas directly inside your web browser to identify the best bus seat for shading.

Choosing the correct side of the bus during long-distance intercity road trips can dramatically improve your travel comfort. Direct sunlight beating through a bus window for hours can create uncomfortable heat, render phone or laptop screens unreadable due to glare, and block you from resting or sleeping comfortably. This calculator tells you exactly how to seat yourself—whether you wish to stay cool in the shade or bask in the daylight views.

Our tool is optimized for popular American transit systems such as Greyhound, Megabus, BoltBus, and regional charter buses. By specifying your starting and ending cities, the system automatically retrieves location coordinates via geocoding APIs and builds a real-time, hour-by-hour visual simulation of your route.

The calculator performs a real-time, step-by-step math analysis of your journey. Here is the step-by-step breakdown of how the sun side advice is generated:

1. Geocoding Lookup: The tool uses the OpenStreetMap Nominatim API to query the starting and ending locations, instantly retrieving their precise latitudes and longitudes. It specifically prioritizes US results to keep city lookups fast and accurate.
2. Geodesic Bearing Calculation: We determine the absolute heading angle (measured in degrees from 0° North) of the bus along the route. For example, traveling from New York City to Boston gives a northeast heading of approximately 50°.
3. Solar Astronomy Formulas: For the specific date and hour of your departure, we calculate the sun's Azimuth (its compass angle relative to true North) and Elevation (how high the sun is above the horizon).
4. Relative Solar Angle: By subtracting the route bearing from the solar azimuth, we determine the relative position of the sun with respect to the bus windows. If the relative angle is between 15° and 165°, the sun is on the right side. If it is between 195° and 345°, it shines from the left side.
5. Time-Series Simulation: If your trip lasts several hours, the tool interpolates coordinates along the route and recalculates the sun's changing position at each hour. It accumulates these values to provide a single, unified seating recommendation for the entire journey.

Depending on your direction of travel, the morning and afternoon sun will strike your bus differently:

• New York, NY to Boston, MA (Northeast): During morning trips, the sun rises in the east (right/front-right of the bus), shifting to the right side by the afternoon. Sitting on the left side is generally best to stay in the shade.
• Los Angeles, CA to San Francisco, CA (Northwest): On a daytime southbound trip, the sun will start on your right (morning east) and end on your left (afternoon west). Choosing the right side is generally best for morning journeys, whereas the left side remains cooler in the afternoon.
• Miami, FL to Orlando, FL (Northbound): Traveling north in the Northern hemisphere means the sun is generally positioned to your right in the morning (East) and your left in the afternoon (West). Select the left side in the morning and right side in the afternoon for shade.
• Chicago, IL to Minneapolis, MN (Northwest): Traveling northwest in the afternoon means the sun is shining directly on your left (West/Southwest). Sit on the right side of the bus to avoid direct solar glare.