"Pag-ibig" suggests a more intense level of love and when directed at people would most likely mean romantic love. "Pagmamahál" is more general in application.
You can have "pagmamahal" towards everyone you know, but it would sound improper if you'd have "pag-ibig" towards your parents, siblings, children, relatives, and friends other than that special someone in your life.
Formal Rank: #750 Casual Rank: #506 ** A lower rank means the word is used more frequently. For example, rank #1 would be the most frequently used word.
Method: This script ranks all words by frequency using both formal sources (mostly newspaper articles) and informal sources (a combination of over 100 hours of transcribed audio, internet comments, and amateur fiction writing) to roughly determine whether a word is used more frequency in casual or formal contexts.
Pag-ibig Example Sentences in Tagalog: (13)
Example sentences created by professional Filipino teachers and writers.