Measure calmly
Finger size changes with temperature, time of day, salt, and activity.
A custom ring can start with the story first. If size is uncertain, treat it as a production detail to confirm before the ring is made.

Finger size changes with temperature, time of day, salt, and activity.
Wider bands can feel tighter than narrow rings in the same size.
Do not guess on a surprise gift if there is time to confirm.
Measure more than once, ideally when hands are at a normal temperature. A ring that barely passes the knuckle in the morning may feel too tight at night. Wider bands also need more comfort room than narrow rings.
If the ring is a gift, design first and confirm size before production when possible. The story and artwork can move forward while the practical fit detail is handled carefully.
The design can be started first, but size should be confirmed before production.