Food waste

The average New Zealand household wastes an estimated $1,364 per year in food, based on a Rabobank-KiwiHarvest study of NZ household food waste (2025). Savings are estimated as a proportion of this baseline, scaled using square root scaling (sM) to reflect the partially shared nature of household food preparation and storage.

Households that waste food “often” are estimated to waste above the average baseline. The savings ranges reflect the reduction in wasted food cost from changing habits — buying in smaller quantities, meal planning, and using leftovers.

Source: Rabobank-KiwiHarvest NZ Household Food Waste Study 2025; Stats NZ Household Economic Survey 2023.

Red meat

Savings are estimated from the cost difference between red meat meals and their lower-cost alternatives, using a meal-cost methodology rather than average household expenditure data. This approach is more accurate for households that regularly eat red meat, since population-average expenditure figures understate the saving for frequent consumers by including households that rarely purchase red meat.

Typical occasion cost for red meat for a 2.5-person household: $30–$60, depending on cut (mince to premium steak). Home-cooked replacement (chicken, legumes): $10–$15. Net saving per occasion: $15–$45. Frequency assumptions: “most days” = 5 occasions per week; “a few times a week” = 2.5 occasions; “around once a week” = 1 occasion.

Source: Stats NZ Food Price Index (FPI) 2025–26; AgResearch NZ consumer meat consumption survey 2023.

Chain takeaway

Savings are estimated from the cost of chain restaurant and food delivery app meals compared with home cooking, using a meal-cost methodology. Chain takeaway for a 2.5-person household typically costs $35–$60 per occasion (fast food to app delivery with fees). Home cooking equivalent: $10–$15. Net saving per occasion: $20–$45.

Frequency assumptions: “more than once a week” = 2 occasions per week; “2–4 times a month” = 3 occasions per month; “once a month or less” = 12 occasions per year.

This question concerns chain fast food and delivery apps only — not local independent cafes and restaurants, which GoZero actively encourages as part of local community economy building.

Source: NZ food cost surveys 2024–25; Stats NZ Household Economic Survey 2023.

Mobile phones

Savings reflect the difference in annualised replacement cost between more and less frequent upgrade cycles. A typical smartphone in NZ costs $700–$1,500. Extending replacement from annually to every three to four years reduces annualised cost by roughly $175–$300 per person per year. Savings are scaled linearly by household size (sL).

Source: Canstar NZ Mobile Phone Market Report, April 2026; MoneyHub NZ Mobile Plan Comparison 2026.

Mobile phone plans

Savings reflect the difference between premium and budget mobile plan costs. Premium plans in NZ typically cost $65–$120 per month; budget and prepay plans $15–$35 per month. Savings are scaled linearly by household size (sL) to reflect multiple household members potentially on expensive plans.

Source: Canstar NZ Mobile Plan Comparison, April 2026; MoneyHub NZ.

Other devices (computers, tablets, TVs, gaming consoles)

Savings are estimated from the difference in annualised replacement cost between current upgrade habits and extending device life. A laptop or TV typically costs $800–$2,500. These figures are not scaled by household size as devices are typically shared.

Source: Canstar NZ; Consumer NZ product life expectancy research.

Streaming services

Savings are calculated from actual NZ subscription costs. Monthly costs used: Netflix standard $22.99, Disney+ $19.99, Neon $19.99, other streaming services approximately $14–$18 per month. Savings represent the full annual cost of cancelling unused services. The question asks only about services the household does not regularly use — an intentionally conservative framing.

Source: Published NZ subscription pricing, May 2026.

Other subscriptions (gym, music, software, gaming, news, AI)

Monthly cost assumptions: gym $55; music streaming $16; software/cloud $14; gaming $15; news/magazines $12; AI tools $25. Annual savings are calculated as monthly cost × 11–13 months, reflecting variation in exact plan costs.

Source: Published NZ pricing for common services, April–May 2026.

Satellite / cable TV

Savings are based on published Sky NZ subscription pricing. Standard packages cost $55–$100+ per month. Cancelling saves $660–$1,200 per year; downgrading saves $300–$600 per year. Unscaled as satellite TV is a household-level subscription.

Source: Sky NZ published pricing, May 2026.

Clothing and footwear

The Stats NZ Household Economic Survey 2023 reports average clothing and footwear spending of $35 per week per household. This is a population average that includes households that rarely buy new clothing; frequent buyers spend significantly more. The upper end of savings ranges for weekly shoppers reflects households spending $60–$100+ per week. Savings are scaled linearly (sL).

Source: Stats NZ Household Economic Survey 2023.

Homewares and furniture

Stats NZ HES 2023 reports average household spending on furnishings and household equipment of approximately $70 per week. As with clothing, this is a population average; frequent buyers spend significantly more. Savings are scaled using square root scaling (sM) to reflect the partially shared nature of household goods.

Source: Stats NZ Household Economic Survey 2023.

Insurance

Savings are estimated from the difference between current insurance premiums and the best available comparable cover obtained through comparison shopping. NZ households that have not compared insurance in the past two to three years typically pay 15–30% more than the best available comparable price. Unscaled as insurance is a household-level cost.

Source: Quashed NZ Insurance Comparison Market Report, Q4 2025.

Heating behaviour (thermostat and room management)

Savings are estimated from electricity cost reductions from behavioural changes, using the Wellington residential electricity price of 34.61 cents per kWh (MBIE, November 2025). Reducing the thermostat by one degree Celsius saves approximately 5–10% of heating energy. Heating only occupied rooms reduces energy use by 20–30% compared with heating the whole home.

These figures reflect behaviour change only — switching to a heat pump or other electrification technology produces larger savings but requires capital investment of $3,000–$8,000. See Rewiring Aotearoa and EECA for guidance on electrification pathways. Savings scaled using square root scaling (sM).

Source: MBIE Quarterly Survey of Domestic Energy Prices (QSDEP), November 2025; EECA home heating efficiency guidance; BRANZ NZ housing energy performance data.

Heat pumps, solar panels, EVs and other technologies

GoZero does not calculate savings from electrification technologies in the estimator, for two reasons. First, these technologies require capital investment of $3,000–$15,000+ and are not available to all households, particularly renters. Second, electrification can reduce energy costs but also increases demand for materials and manufacturing — the net sufficiency benefit depends heavily on what the savings are redirected toward.

GoZero’s view is that where households have already invested in electrification technologies, redirecting those savings toward household resilience and community investment — rather than further consumption — represents exactly the kind of reallocation the sufficiency-first approach is designed to support. For this reason, users can enter their own estimated monthly electrification saving, which is included in total savings and Resilience Fund calculations.

Figures entered are self-reported and not verified. The estimator caps entries at $500 per month to limit implausible figures. Users can find detailed running cost estimates at the EECA vehicle running cost calculator and through electricity retailer monitoring tools.

Source: EECA; Rewiring Aotearoa; electricity retailer monitoring tools.

Overview and approach

Transport savings are calculated differently from household savings. Rather than using population-average expenditure data, the transport calculator uses a vehicle-by-vehicle cost model based on Wellington-specific assumptions. This produces more accurate estimates for the specific decision a household is considering.

All figures assume approximately 9,000 km per year of driving — consistent with the New Zealand average for Wellington urban households (NZTA, 2024). Fuel price assumption: $3.40 per litre (May 2026). Public transport replacement costs use Metlink Snapper card fares.

Transport savings are shown separately from household savings in the Savings Viewer and are not included in the Resilience Fund. This is intentional: going car-free or downsizing is a major structural life change that requires careful planning. The Resilience Fund is based on savings that can be realised relatively quickly from behaviour changes; transport savings may take months or years to fully materialise.

Vehicle running costs

Annual fixed and variable costs by vehicle category (Wellington, 2026):

• Small hatch / sedan: $2,200 fixed (insurance, rego, WoF, servicing) + $0.42/km running = $5,980/yr at 9,000 km
• Medium sedan / SUV: $2,800 fixed + $0.46/km = $6,940/yr
• Large SUV: $3,400 fixed + $0.53/km = $8,170/yr
• Ute / 4WD: $3,800 fixed + $0.54/km = $8,660/yr

Destination parking is optional and scales proportionally with commute days: $80 per week × commute days/5 × 48 weeks per year. At 5 days per week this adds $3,840 per year.

Depreciation is tracked separately using a 16-year curve derived from NZ used vehicle market data. It is shown in the detailed workings but excluded from the primary savings figure, as it is recovered at point of sale rather than as ongoing cash flow.

Source: AA NZ Vehicle Running Costs Guide 2025–26; NZTA vehicle registration data; IRD kilometre rates 2026.

Vehicle values and tiers

Vehicle current value is estimated using a depreciation curve applied to the estimated new price for the selected vehicle category and tier:

• Budget (older or entry-level): small $10k, medium $20k, large $50k, ute $28k
• Standard (typical mid-range): small $22k, medium $42k, large $78k, ute $52k
• Premium (higher-spec or newer): small $33k, medium $60k, large $105k, ute $72k

These represent estimated new vehicle prices in the NZ market (May 2026) including GST. The depreciation curve assumes the vehicle loses value at rates consistent with NZ used vehicle market data: approximately 20% in year one, reducing to approximately 4% per year by year ten.

Source: NZ new and used vehicle market pricing research, May 2026; AA NZ depreciation guidance.

Alternative transport costs

For households going car-free, the calculator subtracts estimated replacement transport costs:

• Active travel (e-bike / cycling): $4,500 one-off purchase + $200/yr maintenance
• Public transport (Metlink): Snapper card fares based on commute distance and frequency, annualised over 44 weeks. Fares: short (<3 km) $2.68; typical (3–15 km) $4.67; long (15–35 km) $6.39; regional (35+ km) $12.78 per trip.
• Mix of both: Half public transport commute + e-bike costs

Non-commute trips are assumed to be replaceable by active travel, local trips, or occasional car sharing at negligible net cost. This is a Wellington-specific assumption reflecting the density and walkability of most Wellington urban areas.

Source: Metlink Wellington published Snapper fares, May 2026; e-bike market pricing NZ.

Rough estimates

When a household chooses “Give me a rough estimate” rather than the precise calculator, savings are shown as ranges based on vehicle operating costs across all categories, net of a typical public transport replacement cost of approximately $2,000 per year. Parking costs are excluded from rough estimates as they are unknown without vehicle-specific information. These ranges are:

• Going car-free (one car): $4,000–$7,000/yr
• Reducing to one car / going car-free (two cars): $4,000–$7,000 / $8,000–$14,000/yr
• Reducing to two / one / car-free (three cars): $4,000–$7,000 / $8,000–$14,000 / $12,000–$21,000/yr

The precise calculator above gives a more accurate figure by accounting for your specific vehicle type, age, commute pattern, and parking costs.

The rebound effect

GoZero’s sufficiency-first approach explicitly addresses the rebound effect — the tendency for savings from reduced consumption to be spent on other goods and services, potentially offsetting environmental benefits. The Resilience Fund mechanism is designed to redirect savings toward household resilience, local businesses, and community investment rather than further consumption. This is why the Savings Viewer shows not just how much you could save, but where those savings could go.

What is not included

The following are deliberately excluded from savings calculations:

• International travel — financial savings from reducing overseas holidays are real but depend heavily on individual travel patterns and are not modelled.
• Electrification capital costs — the upfront cost of heat pumps, solar, and EVs is not subtracted from savings. Users who have already invested in these technologies can include their ongoing savings via the self-reported field.
• Transport depreciation — shown in the detailed workings section of the transport calculator but not included in the primary savings figure, as it is recovered at point of sale.

Prices and data currency

All figures are in New Zealand dollars and reflect NZ market prices as of April–May 2026. Prices change over time; this methodology page is updated periodically to reflect significant changes in source data.