To make sure my wheels are aligned I use a cheap laser pointer.
Put the bike on stand or side stand, bluetak the pointer to brick. Align front and back wheel, get a piece of wood about six inches wide, mark the middle of the wood and add half of the rear tyre measurement.
Mark the measurement on the wood, place the wood on the front tyre with the centre mark in middle of tyre and outside measurement on laser side.
Place brick and pointer at back wheel so laser crosses both sides of rear tyre and points at wood on the front tyre.
If laser points at outside measure get a tape measure and put it on both rims of front tyre so the laser light shines on the tape measure to see if you have to move rear tyre.