✶ Seat lab · LOREG arts. 162–163
Same votes,
other rules.
Spain elects its Congress by closed-list proportional representation, but in 52 small pieces: each province shares out its own seats by the D'Hondt method, with a 3% floor. Below are the 23 July 2023 votes as the Junta Electoral Central certified them. Change one rule and watch the chamber move.
176 for an absolute majority
| Party | Votes | Seats | vs 2023 |
|---|
Gallagher index —
Each cell is a candidacy's votes divided by 1, 2, 3 … The largest quotients win seats (filled). Greyed rows fell under the threshold.
How seats are shared · art. 163
Divide by one,
two, three…
- Candidacies with less than 3% of the valid votes in the province are left out. Blank ballots count as valid, so they raise the bar without winning anything.
- The rest are ranked by votes, and each total is divided by 1, 2, 3 … up to the number of seats.
- Seats go to the largest quotients. A tie between two quotients goes to the candidacy with more votes in total; an exact tie in totals is settled by lot, and later ties alternate.
- Each candidacy's seats go to its candidates in list order. Voters cannot reorder the list.
- Ceuta and Melilla elect one deputy each: whoever has most votes.
| ÷1 | ÷2 | ÷3 | ÷4 | ÷5 | ÷6 | ÷7 | ÷8 | Seats | |
|---|---|---|---|---|---|---|---|---|---|
| A | 168,000 | 84,000 | 56,000 | 42,000 | 33,600 | 28,000 | 24,000 | 21,000 | 4 |
| B | 104,000 | 52,000 | 34,666 | 26,000 | 20,800 | 17,333 | 14,857 | 13,000 | 2 |
| C | 72,000 | 36,000 | 24,000 | 18,000 | 14,400 | 12,000 | 10,285 | 9,000 | 1 |
| D | 64,000 | 32,000 | 21,333 | 16,000 | 12,800 | 10,666 | 9,142 | 8,000 | 1 |
| E | 40,000 | 20,000 | 13,333 | 10,000 | 8,000 | 6,666 | 5,714 | 5,000 | 0 |
| F | 32,000 | 16,000 | 10,666 | 8,000 | 6,400 | 5,333 | 4,571 | 4,000 | 0 |
A 168,000, B 104,000, C 72,000, D 64,000, E 40,000, F 32,000. The eighth seat costs 42,000 votes: A wins four, B two, C and D one each, exactly as LOREG art. 163.1.c prints it.
The cifra repartidora · 2023
Every quotient,
one province at a time.
The same rule as the table above, for a real province: each candidacy's votes divided by 1, 2, 3 …, every quotient a bar. The plane sits at the smallest quotient that still won a seat; whatever rises through it is a deputy. In a big province the plane is low and small parties reach it; in a small one only the first two or three bars do.
This 3D view needs WebGL. The seat lab above shows the same allocation as a table.
Columns ÷1, ÷2, ÷3 … left to right · bright bars win seats · dim bars do not · 2023 votes, JEC
The real threshold
Three per cent
on paper.
A rough guide to the vote a party needs to win a seat is 75% ÷ (seats + 1), a rule of thumb from electoral research (Taagepera), not a legal figure. By that guide the 3% floor only matters in Madrid and Barcelona; everywhere else the district is so small that the real price of a seat is higher. 29 provinces elect five deputies or fewer, 108 seats in all, where the guide puts the price at 12.5% or more.
| Seats | Provinces (2026) | ≈ vote to win one |
|---|---|---|
| 1 | Melilla, Ceuta | plurality |
| 2 | Soria | 25% |
| 3 | Teruel, Segovia, Ávila, Palencia + 4 more | 19% |
| 4 | La Rioja, Álava, Burgos, Salamanca + 6 more | 15% |
| 5 | Ciudad Real, Huelva, Castellón, Valladolid + 4 more | 13% |
| 6 | Almería, Toledo, Girona, Gipuzkoa + 2 more | 11% |
| 7 | Zaragoza, Granada, Santa Cruz de Tenerife, Pontevedra + 1 more | 9.4% |
| 8 | Balearic Islands, Las Palmas, Biscay, Cádiz + 1 more | 8.3% |
| 10 | Murcia | 6.8% |
| 12 | Alicante, Seville | 5.8% |
| 16 | Valencia | 4.4% |
| 32 | Barcelona | 3.0% |
| 38 | Madrid | 3.0% |
Malapportionment · art. 162
Two seats for every
province first.
The Congress has 350 seats. Ceuta and Melilla get one each, every province gets two, and only the remaining 248 follow population. So a seat in Soria represents 37,884 electors and a seat in Madrid 137,488: a vote in Soria weighs about 3.6 times as much.
Electors on the 2023 roll (Cuadro I of the JEC results), divided by 2026 seats. Rural, depopulated provinces gain; the big cities lose. Changing it needs an organic law; the Constitution itself fixes the province as the constituency (art. 68.2).