Angular size is how wide something appears from where you stand, not its true width, which is why the Moon and the Sun look almost the same size despite the Sun being vastly larger and farther away. The small angle formula relates the true diameter, the distance and the apparent angle: the angle in radians is the diameter divided by the distance. This calculator converts that into degrees, arcminutes and arcseconds using the same units for size and distance, so you can compare planets, craters or a distant building. You can also enter the angle and distance to recover the true size. All arithmetic happens instantly in your browser with nothing sent anywhere.
Angular size is how wide something appears from where you stand, not its true width, which is why the Moon and the Sun look almost the same size despite the Sun being vastly larger and farther away. The small angle formula relates the true diameter, the distance and the apparent angle: the angle in radians is the diameter divided by the distance.
Yes. Angular Size Calculator is completely free, with no sign-up and no usage limits.
Yes. Angular Size Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Angular Size Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.