Electoral Calculus

Electoral Calculus is a UK electoral prediction service founded by Martin Baxter. It publishes constituency-level seat projections and Multilevel Regression and Post-stratification (MRP) models for UK general elections, Scottish Parliament elections, and Senedd elections, widely cited in UK political reporting.

Electoral Calculus published its first 2026 Holyrood MRP on 7 April 2026, based on 4,105 respondents with fieldwork 13-31 March 2026. The model projects the Scottish National Party (SNP) on 67 seats, two above the 65-seat majority threshold — the first projected outright SNP majority since Alex Salmond's 2011 result that triggered the 2014 independence referendum. The same MRP projects the Scottish Conservatives on zero constituency seats — all five current Tory constituency seats (Aberdeenshire West, Dumfriesshire, Eastwood, Ettrick Roxburgh and Berwickshire, and Galloway and West Dumfries) are projected to fall to the SNP — leaving the party with just 9 regional list seats and ceding official opposition status to Scottish Labour (projected 17 seats). Reform UK is projected on 14 regional list seats, zero constituency — making Reform's Holyrood representation entirely list-dependent. The MRP is the most recent pre-election model for the 7 May 2026 Scottish election.

Electoral Calculus's models have become the reference point that other outlets anchor to rather than simply cite. For the 2026 cycle, its Holyrood MRP is consequential precisely because a projected SNP majority carries an explicit independence-referendum mandate attached to it: readers tracking Scotland's constitutional future should treat this model as the primary evidence base, not a polling footnote.