SunCalc · Leaflet · Canvas · Three.js Calculating…

Shade Calculator
for overhangs and Solar Chart

Calculates the shadow over the window and visualizes the real section of the opening: solar ray, overhang blocking, sunlit strip and interior penetration distance. Includes 2D stereographic chart and interactive 3D dome.

Shaded window

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Solar elevation

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Profile angle

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Penetration

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Location

Latitude Longitude

Click on the map or drag the marker to change the location.

Date, time and orientation

Day of year—

Local solar time—

The time is interpreted as local solar time at the location, not clock time. It works the same at any longitude.

24h Solar Player

Press play to see the sun's progress over the window throughout the day.

12:00 / 24:00

Duration

The animation moves the same local solar time control from 00:00 to 24:00 and updates the elevation, section, metrics and the open solar chart.

Facade orientationSouth · 180°

Exact azimuth180°

The bearing is the outward normal of the window plane (N=0°, E=90°, S=180°, W=270°).

Opening geometry

Window widthm Window heightm Floor → bottomm

Height from the interior floor to the bottom of the opening.

Interior depthm Horizontal projectionm Overhang slope%

Slope = drop / horizontal projection × 100. A positive value lowers the outer edge; 100% equals 45°.

Vertical gapm Left extensionm Right extensionm Total overhang widthm

Window width plus extensions. If you edit the total, extensions are split equally to both sides.

Geometric model

The section uses the solar profile angle: tan(αp) = tan(alt) / cos(HSA). For inclined overhangs, drop = projection × slope / 100; the junction with the wall remains fixed. The floor-to-opening height positions the window and penetration is measured from the interior face of the wall.

Settings

Save all current data and restore it later.

Useful links

Instant solar reading

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Window Shadow Solar ray

Solar azimuth

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Relative HSA

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Shadow cut

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Sill height

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Sunlit strip

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Projections and Solar Charts

2D stereographic chart and interactive 3D dome with the annual solar band, paths and current time.

Open charts ⌄

2D Stereographic Chart

Interactive 3D Solar Dome

Drag · Scroll to zoom

Wall / Facade Facade normal Solar band (dome and floor) Summer solstice Equinoxes Winter solstice Analemmas Current sun Overhang / canopy Ray · direct sun Ray · blocked by overhang Sunlit strip on interior floor

Front View · Elevation

Shadow projection of the overhang onto the facade plane and window.

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Annual shading matrix

Monthly heatmap by hour. Collapsed by default for clarity.

Open matrix ⌄

No sun 0–10% 10–35% 35–65% 65–85% 85–100%

Each cell uses the same geometry as the elevation. The symbol “—” indicates no direct sun on the facade (night or sun behind the plane), so it does not count as shade produced by the overhang.

Section View · Interior

Limiting ray, window opening, impact and penetration on the interior floor.

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Automatic overhang optimizer

Recommends projection and slope to protect in summer and allow sun in winter.

View optimal options ⌄

Open the card to calculate recommendations based on the current location, orientation and window.

Geometric estimate with representative solar hours. The selected option only modifies the horizontal projection and slope; you can readjust them afterwards.

Plan View · Shadow on floor

Top-down projection: overhang in plan, window in the wall and sunlit strip cast onto the interior floor.

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Wall / facade Overhang (plan projection) Sunlit strip on floor Ray direction (HSA)

The shape of the sunlit strip depends on the horizontal angle of the sun relative to the facade (HSA): the greater the HSA, the more the light shifts laterally as it penetrates into the room.