Electoral Calculus is a psephological web site which attempts to predict future United Kingdom general election results. It was developed by Martin Baxter and employs scientific techniques on data about Britain's electoral geography.

It has been cited by journalists Andrew Rawnsley

Andrew Rawnsley

Andrew Nicholas James Rawnsley is a British political journalist, notably for The Observer, and broadcaster.-Early life:...

 and Michael White

Michael White (journalist)

Michael White is an associate editor and former political editor of The Guardian.-Early life:White was raised in Wadebridge, Cornwall...

 in The Guardian

The Guardian

The Guardian, formerly known as The Manchester Guardian , is a British national daily newspaper in the Berliner format...

, with reference to the 2010 United Kingdom general election.

Main features

The site includes maps, predictions and analysis articles. It has a separate section for elections in Scotland

Elections in Scotland

Scotland has elections to several bodies: the Scottish Parliament, the United Kingdom Parliament, the European Parliament, local councils and community councils.-Scottish Parliament:...

.

Methodology

The calculations were initially based on what is termed the Transition Model, which is derived from the additive uniform national swing

Uniform national swing

Uniform national swing, or UNS is a system for translating opinion polls, which give overall vote proportions, to expected eventual parliamentary seats in a constituency based first past the post system, as in the UK general elections...

model. This uses national swings in a proportional manner to predict local effects. The Strong Transition Model was introduced in October 2007, and considers the effects of strong and weak supporters.

The models are explained in detail on the web site.