Estimating enrolment and voting at state elections
Introduction
As part of planning for state elections the VEC produces state and district level enrolment and voting estimates. This is to ensure our voting services, such as the number and location of voting centres, cater for all Victorians eligible to vote.
Multiple datasets form the basis of our enrolment and voting projections, including population growth patterns, historical election data, and regular snapshots of the electoral roll. We process and analyse these datasets to develop reliable estimates well before election day.
While necessary to estimate enrolment and voting early in the planning process, these figures rely on several assumptions and will never be 100% correct. Normal and expected factors impacting our projections include the time between developing estimates and an electoral event, and the unpredictability of voter behaviour. However, we continually monitor our projections as more information becomes available to ensure the smooth delivery of voting services during the election period.
Methods and approach for the 2026 state election
Forecasts of enrolment and voting numbers at a state and local level have been developed for the 2026 state election (SE2026) using advanced statistical modelling methods, synthesised with growth and development data. Essential planning and delivery requirements were considered and incorporated as part of the final estimates process to produce projected figures for the SE2026.
The following statistical techniques were used to provide initial forecasts:
Linear regression: forecasting approach to observe how particular trends change over time. From these observations a straight or trend line is constructed through past data values to predict future ones. Enrolment data and voting rates from previous electoral events are plotted to forecast November 2026 values.
Advanced statistical modelling: use of ARIMA (Autoregressive Integrated Moving Average) and SARIMA (Seasonal Autoregressive Integrated Moving Average) techniques to support forecasting of time series data. These models have non-linear capability and use complex algorithms to adapt and account for ‘seasonal’ and other variations in the data. These variations can include spikes in enrolment during elections, outliers caused by major disruptive events, and changes in voting patterns over time.
Results
Projected enrolment
Linear regression modelling, combined with growth and development data and snapshots of the electoral roll, project approximately 4.68 million electors for SE2026. This suggests an overall, statewide rate of elector growth to be around 6.5% compared with enrolment at state election 2022 (SE2022).
Uneven growth patterns are evident throughout Victoria, with the most significant rates of growth occurring in outer-Metropolitan Melbourne, particularly amongst outer-north, west and south-east districts. These forecast growth patterns align with established urban and suburban growth patterns. Stable and less pronounced rates of growth are expected for the inner city and inner-suburban districts, and similarly for regional centres and country areas.
Historical state enrolment totals and 2026 estimated enrolment (as of June 2026)
Early voting
Analysis of early voting patterns at the state and federal levels and using linear regression modelling suggests continued growth in early voting numbers. Based on confidence intervals of 95% we may see early voting continue to increase and comprise as much 60% of total SE2026 votes.
Plans are currently in place to manage any such increase and the VEC will be expanding its early voting venue footprint to meet expected demand. We are also preparing for situations or areas where an expected increase in early voting does not eventuate.
Voting on election day
More advanced statistical methods such as ARIMA and SARIMA modelling techniques are being used to model SE2026 election day voting and other vote types, such as postal voting. While an expected increase in early voting will likely see on the day voting decrease as a proportion of all votes, the total number of people voting on election day is likely to increase slightly due to increased enrolment.
The VEC is refining its voting day venue footprint and operations to ensure we are meeting the preferred voting habits of all electors and will provide a seamless election experience for all participants.