This calculator turns the food inflation you keep hearing about into a real dollar figure for your own weekly shop, so you can see what rising grocery prices are actually costing your household. You enter your weekly grocery spend, the food price inflation over the period you are looking at from Stats NZ food price data, and whether that spend figure was your basket at the start of the period or is what you are paying now. The calculator works the figure forward or backward as needed and returns the extra you are paying each week due to inflation, plus the cost of the same basket then and now, and the extra cost projected over a full year. Seeing the weekly rise turned into an annual figure makes an abstract percentage feel concrete, which is often the nudge people need to start comparing unit prices, switching to specials and house brands, or cutting food waste to claw some of that increase back. It is a two-way calculation built around whatever inflation figure you supply, so the result depends on using a realistic rate for your own basket and timeframe rather than a single national average, since your shopping habits may have moved at a different pace to the food price index. Treat the output as an indicative estimate for budgeting purposes rather than an exact accounting of your grocery bill.
Enter the food price inflation over the period from Stats NZ food price data. The calculator shows the same basket at the higher prices, in dollars per week and per year, to put the rise in real terms. Estimate only.
The calculator applies the food inflation over your chosen period to your weekly shop. If your figure is the spend at the start, it grows it by inflation to show what the same basket costs now. If your figure is your spend now, it works backward to what it cost before. Either way it shows the extra per week and per year, turning an abstract inflation rate into a real number for your budget.
A $250 weekly shop with 20% food inflation since now costs about $300, an extra $50 a week, or roughly $2,600 a year for the same groceries. Seeing that figure is often the push to compare prices and cut waste.
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