Betelgeuse is a red giant star approximately 640 light years from Earth. Since a light year measures about 6 trillion miles in length, Betelgeuse is some 3.8 quadrillion miles away.
The most generally accepted distance to the star is measured by the signature of the radio emissions for its spectral type. Direct parallax measurements from Earth give the distance of Betelgeuse as approximately 495 light years. The parallax method is considered increasingly unreliable for objects greater than 100 light years away, but it is still widely used for some well-known heavenly bodies. Averaging the parallax measurement and the distance calculated by its emissions signature, a compromise distance of 570 light years is sometimes used to denote how far away Betelgeuse is from Earth.