Interactive tool
New Zealand coalition calculator
Adjust the party vote, estimate seats under modified Sainte-Laguë and combine parties to test a parliamentary majority.
Starts from the NZ Polls average · 1 September 2026
Party vote scenario
Move the vote, see the Parliament
Entered party vote: 98.8%
Government builder
This coalition falls short
National + ACT + NZ First
Mechanical seat estimate from the current polling average and electorate assumptions — not a coalition prediction.
How to use the calculator
Move a party's slider or enter a percentage. The seat estimate recalculates immediately. Then select parties under “Build a coalition” to compare their combined seats with the majority line.
What it assumes
Parties qualify if they reach 5% of the party vote or win an electorate. Current electorate-seat assumptions are included for parties already holding seats. The tool uses the official modified Sainte-Laguë allocation principle, but it is an independent explainer—not the Electoral Commission's official calculator.