What are two ways to amend the US Constitution?

The U.S. Constitution can be amended in two primary ways: first, through a two-thirds majority vote in both the House of Representatives and the Senate; second, through a national convention called by two-thirds of state legislatures, where amendments can be proposed. After an amendment is proposed by either method, it must then be ratified by three-fourths of the state legislatures or by conventions in three-fourths of the states. This process ensures that amendments require broad consensus across both federal and state levels.