Congressional Reapportionment Calculator
Calculate how congressional seats would be allocated among states based on population data using different apportionment methods
Population Data
Calculation Options
Apportionment Results
| State | Population | Seats | % of Seats | % of Pop. | Constituents/Seat | Priority Value |
|---|---|---|---|---|---|---|
| Enter data and click calculate to see results | ||||||
Visualization
Visualization will appear here after calculation
📊 Historical Apportionment Methods Comparison
| Method | Used in US | Advantages | Disadvantages | Favors |
|---|---|---|---|---|
| Huntington-Hill (Current) | 1941-present | Minimizes relative differences in district size | Complex calculation | Medium-sized states |
| Webster/Sainte-Laguë | 1842, 1911, 1931 | Unbiased, treats large/small states equally | May produce ties | Neither |
| Jefferson/d'Hondt | 1792-1832 | Simple to calculate | Biased toward large states | Large states |
| Adams's Method | Never | Guarantees each state at least its lower quota | Strong small-state bias | Small states |
| Hamilton/Vinton | 1850, 1870-1900 | Follows quota rule exactly | Alabama paradox possible | Small states |
📚 Apportionment Methodology
Huntington-Hill Method
The current US method uses a geometric mean formula to calculate priority values: PV = P/√n(n+1) where P is state population and n is current seat count.
The Quota Rule
A state's seats should equal either its lower quota (floor of exact proportion) or upper quota (ceiling). Some methods violate this rule.
The Alabama Paradox
When increasing total seats causes a state to lose a seat. Possible with Hamilton's method but avoided by current methods.
Population Trends
Since 1940, seats have shifted from Northeast/Midwest to South/West. Texas gained seats in every reapportionment since 1950.
Note: This calculator provides estimates based on mathematical apportionment methods. Actual congressional apportionment may involve additional legal or political considerations not reflected here.