What this tool does
Shadow Calculator is an educational, browser-based tool that shows how shadow length and direction change with date, time, latitude, and object height.
The app uses the open-source library SunCalc for solar position calculations and Three.js for 3D visualization in your browser. All computations happen locally on your device.
Scientific assumptions
- Flat ground (no terrain or slope).
- Standard geometry:
L = H / tan(α), where H is object height and α is solar altitude. - Approximate city coordinates and time zones, suitable for visualization but not survey-grade work.
Disclaimer
This site is provided for informational and educational purposes only. It is not intended for navigation, engineering certification, safety-critical design, or any use where precise solar position or shadow length is required.
This was created as a fun and quick reference tool for family and friends.
No guarantees are made about the accuracy or completeness of the results. Use at your own risk.
Privacy
This site does not require login and does not intentionally collect personal data. Any parameters you set are processed within your browser. Being deployed with GitHub Pages, GitHub may collect basic technical logs as part of their hosting.
Open-source license
The source code for this site is intended to be open-sourced on GitHub
under the MIT License. See the LICENSE file in the repository
for details.
Questions or comments? See the project repository on GitHub.