Angular Size Calculator
Estimate angular size from physical size and distance using the small-angle approximation.
Estimate angular size from physical size and distance using the small-angle approximation.
Move between orbital motion, gravity, stellar properties, astronomical distance, angular scale, light travel time and telescope optics.
Calculate orbital period from semi-major axis using Kepler’s third law in solar-system units.
Open calculatorEstimate escape velocity from mass and radius expressed in Earth units.
Open calculatorEstimate stellar luminosity relative to the Sun from radius and effective temperature.
Open calculatorCalculate astronomical distance from apparent and absolute magnitude.
Open calculatorEstimate angular size from physical size and distance using the small-angle approximation.
Calculate how long light takes to cross a distance expressed in astronomical units.
Open calculatorCalculate telescope magnification from telescope and eyepiece focal lengths.
Open calculatorAngular Size Calculator is an educational astronomy tool for exploring a standard quantitative relationship.
Enter the requested values using the stated units. The calculator validates the numerical domain and applies θ(arcsec) = 206265 × size / distance.
Variables: size = Physical size; distance = Distance (same unit).
Example: size = 1, distance = 206265 in the same unit → θ = 1 arcsec.
It is intended for astronomy study, classroom exercises and understanding the quantitative relationship represented by the model.
No. Astronomy formulas often rely on simplifying assumptions, approximations or specific unit conventions. Interpret the result within the stated model.
These sources are used to verify terminology, formulas, and information related to this calculator.