NZ Budget Planner Calculator 2026

Always take-home pay. Budgeting from your gross salary overstates available money by the full amount of PAYE, ACC earner levy, KiwiSaver and any student loan deduction — which together can be a substantial share of the headline figure.

Convert weekly amounts by multiplying by 4.333 (52 ÷ 12) rather than 4. Using 4 quietly understates a year of rent by about a month, and it is the most common arithmetic error in New Zealand household budgets.

There is no universal figure, and high housing costs make rigid rules unrealistic for many households. More useful than a target is the direction of travel: whether your surplus is positive and whether it is growing over time.

Build the budget on a conservative typical month rather than a good one, and treat surplus in strong months as a buffer for lean ones. Contract, seasonal and self-employed earners also need to set aside provisional tax and ACC levies.

Almost always because annual and irregular costs were left out — car registration and WOF, insurance excesses, dental visits, Christmas. Divide each yearly cost by twelve and include it as a monthly line.