Congress has two chambers: the House of Representatives and the Senate. Both write laws, but they are built differently and handle some different jobs. Knowing how they compare helps you understand who represents you and how a single idea turns into a national law.
Size: 435 versus 100
The House has 435 voting members. The Senate has 100. The House is larger because its seats are split among the states by population, so a big state like California has many more House members than a small state like Wyoming. The Senate is fixed: every state gets the same number of senators no matter how many people live there.
How representation works
In the House, the country is divided into 435 districts of roughly equal population, about 760,000 people each, and every district elects one member. Your House member represents only the people inside your district. The Senate is set up differently. Each state elects two senators, and they represent the whole state rather than one slice of it. That is why you have one Representative but two senators. For more on the House side of this, see What Does a U.S. Representative Do?
Term length: two years versus six
House members serve two-year terms, and all 435 seats are up for election in every even-numbered year. Senators serve six-year terms, and the terms are staggered so that about one-third of the Senate is up for election every two years. The longer Senate term gives that chamber a steadier, longer view, while the short House term keeps members close to current public opinion.
What each chamber does
Most legislation can start in either chamber, and a bill must pass both the House and the Senate in identical form before it can become law. Each chamber also has special powers. The House starts all revenue bills and can impeach federal officials. The Senate confirms many presidential appointments, including federal judges and Cabinet officials, approves treaties, and holds the trial when an official is impeached. The House is led by the Speaker, chosen by its members. The Senate is presided over by the Vice President, who can cast a tie-breaking vote.
How they work together
Because a bill has to clear both chambers in the same form, the House and Senate often pass slightly different versions and then settle the differences before a final vote. To see the full path a proposal takes, read How a Bill Becomes Law.
Why Congress has two chambers
The two-chamber design was a compromise written into the Constitution. Large states wanted representation based on population, which the House provides. Small states wanted equal footing, which the Senate provides with two seats each. Splitting Congress this way means a bill has to win support both from populous areas and from a broad range of states before it can become law. The result is a slower process with more checks, which is what the design intended.
Powers unique to each chamber
The Constitution gives each chamber its own jobs. Bills that raise revenue must start in the House, which also holds the power to impeach an official. The Senate confirms presidential nominations, including federal judges and cabinet officers, ratifies treaties by a two-thirds vote, and holds the trial when the House impeaches. So a Supreme Court nominee or a treaty goes through the Senate, while a tax bill begins in the House.
How each chamber is led
Leadership looks different in each chamber. The House is run by the Speaker, who is elected by the members and sets the agenda for the majority. The Senate is led day to day by the majority leader. The Vice President is the formal president of the Senate and can cast a tie-breaking vote, which matters when the chamber is split evenly. These roles give the majority firmer control in the House than in the Senate.
Different rules, different pace
The House and Senate move at different speeds. House rules let the majority limit debate and bring a bill to a vote quickly. Senate rules give individual senators more power to slow things down, most visibly through the filibuster. As a result, the House can act fast on a party-line vote, while the Senate often needs broader agreement to finish a bill. The two paces are a frequent source of friction between the chambers.
Why a bill needs both chambers
A bill becomes law only if the House and the Senate pass the same text. Because the two chambers have different sizes, terms, and rules, they often produce different versions of the same idea. When that happens, members work out a single compromise text that both chambers vote on again. This shared requirement is the main check the two chambers hold over each other, and it is why a party that controls only one chamber cannot pass a law on its own.
Side by side
- Seats. House 435 voting members. Senate 100.
- Term. House two years. Senate six years, with about a third of seats up every two years.
- Who elects them. House members are elected by one district. Senators are elected by an entire state.
- Minimum age. House 25. Senate 30.
- Citizenship required. House seven years. Senate nine years.
- Presiding officer. The Speaker of the House. The Vice President of the United States serves as President of the Senate and votes only to break a tie.
Which chamber acts first
The Constitution gives the House the first move on revenue. Article I, Section 7 provides that all bills for raising revenue originate in the House, though the Senate may propose amendments as it does on other bills. In practice the Senate can and does rewrite tax bills substantially once they arrive.
The House brings impeachments and the Senate tries them, with conviction requiring two thirds of senators present. The Senate alone confirms judges and other appointments and ratifies treaties, also by two thirds.
Why the Senate moves more slowly
The House sets terms of debate through its Rules Committee, so a bill can move from committee to a floor vote quickly and amendments can be limited. The Senate has no equivalent gatekeeper. Debate generally continues until senators agree to stop, and ending debate over objection takes a cloture vote, normally 60 of 100 senators.
What this means for you
You have one House member, decided by where you live, and two senators shared with everyone in your state. Contact your House member about a local matter or a federal agency case, and either senator about statewide questions. See how to contact your member of Congress, or find your district and representative and your senators by state.
Sources
Chamber sizes, term lengths, qualifications and presiding officers come from the U.S. Constitution, Article I, and from the official reference material published by the U.S. House of Representatives and the U.S. Senate. The revenue origination rule comes from Article I, Section 7. Impeachment, confirmation and treaty roles come from Article I, Section 3 and Article II, Section 2. Cloture practice comes from the Standing Rules of the Senate. Checked August 12, 2026.
To find your own Representative and the district you live in, use the lookup on the home page.
Last updated August 13, 2026.
