How Is Stv Calculated

An STV election count starts with a count of each voter’s first choice, recording how many for each candidate, calculation of the total number of votes and the quota and then taking the following steps: A candidate who has reached or exceeded the quota is declared elected.

What formula does STV use?

Each winner’s surplus votes transfer to other candidates according to their remaining preferences, using a formula (p/t)*s, where s is a number of surplus votes to be transferred, t is a total number of transferable votes (that have a second preference) and p is a number of second preferences for the given candidate.

How does the additional member system work?

In an election using the additional member system, each voter casts two votes: a vote for a candidate standing in their constituency (with or without an affiliated party), and a vote for a party list standing in a wider region made up of multiple constituencies.