Window Sunlight Exposure Estimator

How This Tool Works

This window sunlight exposure calculator estimates sunlight hours for windows based on two key factors: window orientation (north, south, east, or west) and season (spring, summer, fall, winter). It uses solar position data and the sun\'s path across the sky to determine how many hours of direct and indirect sunlight each window direction receives throughout the day. The calculations account for the sun\'s angle, which changes significantly by season.

In the Northern Hemisphere, south-facing windows receive the most sunlight (6-10 hours in summer, 4-6 hours in winter) because the sun travels across the southern sky. North-facing windows receive the least direct sunlight (mostly indirect light). East windows get morning sun, while west windows get afternoon sun. The tool helps you understand light conditions for plant placement (matching plants to their light needs), home design (optimizing natural lighting), and energy planning (passive solar heating, cooling considerations).

Window Orientation Guide

• South Windows: Receive the most sunlight (6-10 hours), best for sun-loving plants and natural lighting
• North Windows: Receive indirect light (1-3 hours), best for low-light plants and reducing glare
• East Windows: Receive morning sunlight (3-6 hours), good for plants that prefer bright but not intense light
• West Windows: Receive afternoon sunlight (2-7 hours), can be intense, good for sun-loving plants with afternoon protection

FAQ

• Which window direction gets the most sun?
  South-facing windows receive the most direct sunlight throughout the day, especially in the Northern Hemisphere. They get 6-10 hours of sunlight in summer and 4-6 hours in winter. East windows get 3-6 hours of morning sun, west windows get 2-7 hours of afternoon sun (can be intense), while north windows get the least (1-3 hours of indirect light). In the Southern Hemisphere, north-facing windows get the most sun.
• How does season affect window sunlight?
  Sunlight hours vary significantly by season due to the sun's changing angle. Summer provides the most hours (especially for south-facing windows), with longer days and higher sun angle. Winter provides fewer hours, with shorter days and lower sun angle. Spring and fall provide moderate hours. North-facing windows get minimal direct sunlight year-round, mostly indirect light.
• What plants work best for each window direction?
  South windows: sun-loving plants (succulents, cacti, herbs, tomatoes, peppers). East windows: medium-light plants (ferns, peace lilies, African violets, begonias). West windows: plants that tolerate intense afternoon sun (succulents, some herbs, jade plants). North windows: low-light plants (pothos, snake plants, ZZ plants, philodendrons). Consider using grow lights for plants that need more light than your windows provide.
• How do I measure window orientation?
  Use a compass or compass app on your phone. Stand facing the window (inside or outside) and note the direction. North is 0°/360°, East is 90°, South is 180°, and West is 270°. Windows facing these directions get corresponding sunlight patterns. For windows between directions (e.g., southeast), estimate based on the closest cardinal direction or use the calculator for the primary direction.
• How does window sunlight affect home energy costs?
  South-facing windows can provide passive solar heating in winter, reducing heating costs, but may increase cooling costs in summer. North windows provide consistent indirect light with minimal heat gain. East and west windows can cause heat gain in summer. Consider window treatments (curtains, blinds) and energy-efficient windows to manage sunlight and temperature. Proper window placement and shading can significantly impact energy costs.
• Can I increase sunlight for a window?
  You can increase sunlight by removing obstructions (trees, buildings), using reflective surfaces, installing skylights or light tubes, using mirrors to redirect light, and choosing lighter wall colors. However, window orientation is fixed, so you're limited by your home's design. For plants, consider grow lights to supplement natural light, especially for north-facing windows or during winter months.