What is the meter of a sonnet

A sonnet is a form of poetry that has a long historical tradition and it is different in the various European traditions that developed it. As for the English sonnet, also called Shakespearean sonnet (Shakespeare brought this form of poetry to its perfection, arguably), it is composed of three quatrains (four-line stanzas) and a final couplet. This kind of sonnet follows an iambic pentameter as its meter (the meter is the basic rhythmic structure of a line or a poem). Iambic refers to how rhythm is measured in groups of syllables called feet (in this case, iambic, the foot is characterized as having an unstressed syllable followed by a stressed one). Pentameter means that the line is composed of five feet.

Answer: It can vary, however Shakespeares' sonnets were written in iambic pentameter.