Most Astros between 1985 to 2002 will have a rim size that is either:
Most Astros between 2003 and 2005 will have a rim size that is either:
Usually, the rim size is imprinted on the back side of the hub. The figure should include diameter, width, and bolt pattern. You can also measure yourself with a measuring tape from the bottom of the bead on the back to the other.
Luckily, Astros can take more than just Astro wheels! There’s still hope for your vintage van!