How does the d’Hondt method allocate seats in a party-list election?

The d’Hondt method is a largest-average formula used in party-list proportional representation to allocate legislative seats. Under this system, seats are awarded one at a time to the party with the highest average number of votes.1

The allocation process follows these steps:

• Initial Calculation: The first seat is awarded to the party with the highest total number of votes.1
• Divisor Adjustment: For each subsequent seat, the party’s total vote count is divided by the number of seats it has already been awarded plus one.1
• Sequential Awarding: After a party wins a seat, its divisor increases (e.g., dividing by 2, then 3, and so on), which reduces the party's average and its likelihood of winning the next seat.1

This process repeats until all available seats in the district are distributed. Because this method tends to slightly overreward larger parties, it can make it more difficult for smaller parties to gain representation compared to other systems like the Sainte-Laguë method or greatest-remainder formulas.1