Pennsylvania
17 congressional districts.
Map
- Very compact (0 to 19)
- Compact (20 to 39)
- Middle (40 to 59)
- Irregular (60 to 79)
- Very irregular (80 to 100)
Select a district for details.
The area outlined with dashes on the map, enlarged so its smaller districts can be seen.
Map used in 2026
Court-adopted plan (Carter v. Chapman)
- Drawn by
- a court
- Enacted
- 2022-02-23
- Changed since 2024
- No
Source: All About Redistricting, Loyola Law School (secondary source) (checked 2026-11-04)
Districts
| District | Irregularity | National rank |
|---|---|---|
| PA-01 | Irregularity score 22 Compact | 361st least compact |
| PA-02 | Irregularity score 24 Compact | 350th least compact |
| PA-03 | Irregularity score 51 Middle of the pack | 200th least compact |
| PA-04 | Irregularity score 81 Very irregular | 58th least compact |
| PA-05 | Irregularity score 48 Middle of the pack | 214th least compact |
| PA-06 | Irregularity score 45 Middle of the pack | 238th least compact |
| PA-07 | Irregularity score 25 Compact | 345th least compact |
| PA-08 | Irregularity score 39 Compact | 271st least compact |
| PA-09 | Irregularity score 55 Middle of the pack | 183rd least compact |
| PA-10 | Irregularity score 52 Middle of the pack | 196th least compact |
| PA-11 | Irregularity score 18 Very compact | 380th least compact |
| PA-12 | Irregularity score 45 Middle of the pack | 236th least compact |
| PA-13 | Irregularity score 19 Very compact | 374th least compact |
| PA-14 | Irregularity score 36 Compact | 295th least compact |
| PA-15 | Irregularity score 13 Very compact | 398th least compact |
| PA-16 | Irregularity score 23 Compact | 358th least compact |
| PA-17 | Irregularity score 45 Middle of the pack | 232nd least compact |
Scores describe shape, not intent. How scores work
Pennsylvania's senators
- John Fetterman, Democrat
- David McCormick, Republican
Senators are elected by the whole state, so district lines don't change who they are. Senators serving as of November 6, 2026. Senators elected in November 2026 take office January 3, 2027. Where this comes from
Partisan fairness
How the 2024 presidential vote splits across these districts. Kamala Harris (Democrat) won 49.1% of the two-party vote and carried 8 of 17 districts.
- Efficiency gap
- 0.5% Favors Republicans
Counts each party's wasted votes: votes for a losing candidate, plus a winner's votes beyond the half needed to win. The gap is the difference between the two parties' wasted votes, as a share of all votes.
- Mean-median difference
- 1.0 points Favors Republicans
The gap between a party's average vote share across the districts and its share in the middle (median) district. When the middle district leans away from a party's average, that party's voters are packed into a few lopsided districts.
- Declination
- 0.03 Favors Republicans
Compares how lopsided each party's wins are. A party that wins a few districts by huge margins and loses the rest narrowly is at a disadvantage. Runs from 0 (even) to 1.
Votes are 2024 presidential results by precinct, added up within each district. This state used the same districts in 2024 and 2026. These measures show how a map turns one election's votes into seats. They don't show why the lines were drawn, and they shift from one election to the next. How fairness scores work