Voting ends when polls close, but election workers continue counting ballots for days (or even weeks) after. This is a long process that ensures every vote is counted accurately.
During this time, local and state election officials review informal results (i.e., those reported on election night or in the days after) and add any outstanding ballots deemed eligible for counting during the canvass (i.e., mail ballots verified as received by the deadline, or provisional ballots that have been verified as cast). Only once this process is complete will we know the “certified results.”
While the number of votes won by a candidate is often obvious to most voters, the underlying details of how election results are calculated can be confusing. To help you better understand what happens behind the scenes, we’ve compiled some helpful information below.
Vote reporting systems link data sources to make a prediction about the winner of each race before all votes have been counted. The exact calculations used by different news outlets vary, but each uses a variety of inputs including exit polls, the total number of early in-person and mail ballots, and patterns from past elections.
Once a media outlet has called a race, they will likely dedicate less coverage to ongoing vote counting. However, these outlets still provide updates on their progress towards a completed result for each race. News outlets also frequently compare their statistical models to the actual final results for each race in order to evaluate how well they predicted the outcome.