🔧 Free Astronomy Tools & Calculators
Professional-grade astronomy calculators for stargazers and astrophotographers. No registration required - all tools are completely free to use.
Field of View Calculator
Calculate the true field of view for any telescope and eyepiece combination. Essential for observation planning and target framing.
Magnification Calculator
Determine magnification power and maximum useful magnification for your telescope setup. Includes guidance for different celestial objects.
Astrophotography Exposure Calculator
Optimize exposure settings for deep sky astrophotography. Calculate optimal ISO, exposure time, and frame counts.
Astronomy Red Light
Preserve your night vision with this red light screen. Perfect for reading charts and adjusting equipment during nighttime observations.
🌟 Why Use Stargazer.tools?
Completely Free
No registration, no subscriptions, no hidden fees. All tools are 100% free to use.
Mobile Friendly
Use on any device - desktop, tablet, or phone. Perfect for field observations.
Educational
Learn while you calculate with detailed explanations and astronomy tips.
🔭 For Visual Observers
Whether you're a beginner with a small refractor or an experienced observer with a large reflector, these tools help you get the most from your telescope.
- • Calculate the best eyepiece for each object
- • Understand your telescope's capabilities
- • Plan observations with field of view knowledge
- • Learn optimal magnifications for different targets
📷 For Astrophotographers
From DSLR wide-field to dedicated cooled cameras on long focal length telescopes, optimize your imaging setup for better results.
- • Determine optimal exposure settings
- • Calculate field of view for framing
- • Understand the 500 rule and NPF rule
- • Plan imaging sessions effectively
🚀 More Tools Coming Soon
We're constantly adding new calculators and tools to help astronomers and astrophotographers.
🌙 Lunar Calculator
Moon phases and visibility
🪐 Planet Finder
Planetary visibility calculator
⭐ Star Chart Generator
Custom star charts for your location