Find the right tool
for the sky above.
Twenty precise astronomy tools for planning an observing session, checking the sky, or working through the physics.
Common observing tasks
Astronomical toolset
Observation Tools
Plan a night under the stars, from live ISS positions to telescope optics.
- ISS Tracker
- Moon Phase
- Telescope Magnification
- Sidereal Time
- + 3 more tools
Calculation & Conversion
Convert dates, distances, and planetary numbers in seconds.
- Planet Weight
- Julian Date
- Distance Converter
- Orbital Period
- + 1 more tool
Physics Tools
Black holes, stellar furnaces, and the expanding universe — real astrophysics.
- Black Hole Radius
- Escape Velocity
- Star Temperature
- Redshift & Hubble
- + 4 more tools
Latest Field Notes
Enter the Journal
PhysicsThe Big Bang Theory
The origins of everything: space, time, and the CMB.
PhysicsDark Matter & Energy
The invisible 95% of the universe explained.
TechnologyThe JWST: A New Eye
How the James Webb Space Telescope reshapes astronomy.
AstronomyLife of Stars
From nebula to supernova: stellar evolution.
ExplorationMars Exploration
Searching for signs of past life on the Red Planet.
ExplorationThe Voyager Mission
Humanity's farthest reach into interstellar space.
Why Choose CosmoToolbox?
Real Scientific Formulas
Every calculator runs on verified equations — from Wien's Law to the Schwarzschild radius — using constants published by NASA and the IAU.
Instant In-Browser Results
All tools compute locally on your device with zero wait, zero installation, and zero server round-trips.
Learn as You Calculate
Each tool includes the formula, a step-by-step user guide, and FAQs, so every answer doubles as a mini lesson.
Privacy First
No accounts, no tracking, no data collection. Your calculations never leave your browser.
Start Exploring the Universe
Whether you're planning tonight's observing session or puzzling over an astrophysics problem, CosmoToolbox has the tool for the job.
Professional Astronomical Data at Your Fingertips
CosmoToolbox is a comprehensive suite of digital tools designed for the modern astronomer. From calculating Schwarzschild radii to tracking the ISS in real-time, our platform provides accurate, verifiable data for both amateur and professional use.
Educational Commitment
We believe that every calculation should be a learning opportunity. That's why every tool in our suite is accompanied by a detailed scientific explanation, user guide, and FAQ section, ensuring that users understand the physics and mathematics behind the cosmos.