The grade is a weighted average of three scores. Change the weights to match what matters to you.
How grades are calculated
Vote attendance
This is the share of roll-call votes the member cast while in office. Voting "present" counts as attending. 100% attendance scores 100 points and 85% or lower scores 0, on a straight line in between. By custom the Speaker of the House votes only occasionally, so the votes they skip as Speaker aren't counted against them. Delegates from DC and the territories are counted only on the votes they are allowed to cast.
Bills written
Bills and joint resolutions the member sponsored, with points for how far each one got: introduced (1), acted on in committee (3), passed a chamber (6), became law (10). The member is ranked against their own chamber: the top member scores 100, the chamber average scores 75 (a C) and the lowest scores 50. Simple resolutions, such as commemorations, don't count.
Bills supported
The number of bills and joint resolutions the member cosponsored, ranked within their chamber the same way: 100 for the top member, 75 for the average, 50 for the lowest.
Letter grade
A ≥ 93, A− ≥ 90, B+ ≥ 87, B ≥ 83, B− ≥ 80, and so on down to F below 60. A member who joined partway through the Congress gets a partial term label. Their bill counts cover less time, so read those grades with care.
Data: rosters from congress-legislators, roll-call votes from Voteview, legislation from Congress.gov. Bill progress is inferred from each bill's latest action.