Pen y Fan is a Hewitt of 886 m in Powys. It is the highest of the 12 register hills recorded in Powys; the next is Cadair Berwyn at 832 m, 54 m lower.
Nothing higher stands within 96.2 km; the nearest higher summit is Cadair Idris – Penygadair (892.7 m), to the north. Only nine of the register's Wales hills are higher. It is also on the county tops list, as the highest point of its historic county. In the database's Llandovery to Monmouth region it is the highest of ten register hills, above Waun Fach and eight others. The key col lies 78.9 km away to the north, at 214.3 m. It counts towards four lists: Hewitts, Nuttalls, Marilyns and county tops. Its drop of 672 m is 76% of its height: the col linking it to higher ground is only 214.3 m above sea level. It overtops all four of its nearest neighbours; the tallest of them, Waun Rydd, reaches 769.2 m. It stands 152 m above its nearest neighbour, Fan Fawr, 4.8 km to the south-west.
