To make the correct measurement for your feet width, Please follow bellow process:
1.Press the feet on the floor, let the feet endure the body weight. Your feet situation should be same when you wear the shoes and walking.
2.Take the soft ruler to measure the circumference of the widest portion of your feet. (around your feet , see the above measurement picture)
3.Please tell us which Euro size usually wear, we can take that as making reference
Heels weren't created to run in and they're not athletic wear. Also, the heels shouldn't be overly slim or else it won't have the skill to support the wearer stably. If it actually is impossible that you simply walk in platform heels that are black, then tend not to stress because you could always select the ones which don't have heels.