Banner Ad Dimensions
Looking for the best guidelines for banner ad standards?
I recommend going straight to the source and using IAB as a reference.
Check out the IAB Display Advertising Guidelines
“IAB released a complete overhaul of the IAB Standard Ad Unit Portfolio, for public comment, updating its digital ad formats to adapt across screens, and to incorporate the LEAN Principles of lightweight, encrypted, AdChoice supported, and non-invasive advertising…”