How it works
- ✓ Enter New Zealand values in NZD.
- ✓ Engine compare uses model nz-paye-acc.
- ✓ Inspect the breakdown, not only the headline.
- ✓ Compare a second scenario.
- ✓ Open related tools: Rent vs buy, Rent affordability, Down payment, Closing costs, Rental yield.
Methodology
## Methodology — Heat pump vs gas bill comparison calculator
1. Normalize inputs. 2. Engine `compare` with New Zealand pack (nz-paye-acc). 3. Social rate 0.016, VAT/GST 0.15 from params.ts. 4. Show KPI + breakdown. 5. Continue with Rent vs buy, Rent affordability, Down payment, Closing costs, Rental yield.
### Heat-pump vs gas method 1. Enter comparable monthly energy spend under each system. 2. Annualize and include maintenance if you track it offline. 3. Payback for equipment belongs in a separate ROI / loan view. 4. Local tariffs and outdoor design temperature drive real savings.
### Engine detail (compare) - Uses shipped model nz-paye-acc for New Zealand. - Social / contribution rate in params: 0.016; VAT/GST: 0.15. - Example anchor income ~ NZ$72,000 (illustrative, not a median claim). - Read the breakdown lines, not only the headline KPI. - Re-run after changing one input to see sensitivity.
Worked examples
Baseline — New Zealand
Start near NZ$72,000 (credit principal NZ$550,000, rent-like NZ$2,200 if housing). Note the primary KPI for Heat pump vs gas bill comparison calculator, then open related calculators in the same journey.
Sensitivity +10%
Raise the main driver to about NZ$79,200 and compare the delta vs baseline — critical for loans, tax brackets and goals.
Household limit
Push housing or debt share until it exceeds a personal comfort threshold (e.g. 30–40% of net income).
Verify before acting
Re-run with your real New Zealand numbers, then confirm with payslip, bank quote or tax authority tools. Educational only.
Common mistakes
1. Headline-only decisions
Read the breakdown and pair with Rent vs buy, Rent affordability, Down payment, Closing costs, Rental yield.
2. Wrong period
Do not mix monthly and annual figures.
3. Ignoring fees
Banks and insurers may add costs beyond pure interest.
4. Wrong country table
This page uses New Zealand (NZ) parameters, model nz-paye-acc.
5. Treating estimates as legal notices
Educational only — keep official statements.
Local deep dive
## Complete guide — Heat pump vs gas bill comparison calculator
New Zealand · NZ · model nz-paye-acc · NZD.
Primary intent: calculate. Secondary: understand, compare, decide.
ACC earner levy / GST 15%
IRD — PAYE educational model.
Related: Rent vs buy, Rent affordability, Down payment, Closing costs, Rental yield
### Editorial standards for this calculator - Transparent model: nz-paye-acc rates live in site params (social 0.016, VAT/GST 0.15). - Primary sources: link to the tax/finance authority for New Zealand in Sources. - No city spam: one intent URL, unique title and FAQ. - User duty: re-run with your documents; keep official statements as source of truth.
### Why this may differ from official numbers May differ from payslip: KiwiSaver and student loan not fully entered.
### Local context — Heat pump vs gas bill comparison calculator This page is oriented to New Zealand (NZ), currency NZD, engine `compare`, tax model nz-paye-acc. IRD — PAYE educational model. Educational estimate for planning conversations — not a binding tax notice, bank quote, or regulated advice.
FAQ
Will a heat pump always cut bills?
Depends on electricity vs gas tariffs, insulation, and climate. Use your utility rates, not generic marketing claims.
What makes this Heat pump vs gas bill comparison calculator page suitable for New Zealand?
It ships the local parameter pack (NZ, model nz-paye-acc), cites methodology/sources, and labels limits. IRD — PAYE educational model. Educational estimate only.
Is Heat pump vs gas bill comparison calculator updated for 2026?
Yes. Parameters target 2026 for New Zealand (model nz-paye-acc).
Is this official advice?
No. In New Zealand, follow the tax authority and licensed professionals. IRD — PAYE educational model.
Why might results differ from my payslip or bank?
Benefits, local fees, progressive detail and rounding differ by payroll vendor and lender products.
Do you store my numbers?
Core calculations run in the browser without requiring an account.
How do you avoid thin spam pages?
Each URL is a distinct intent with unique title, inputs, examples and FAQ — no city template farms.
Can I use this on mobile?
Yes. Static pages are built for fast mobile use.
Who maintains the content?
Calcly New Zealand financial content team with YMYL review and visible update dates.
Which currency is used?
Default money formatting uses NZD.
Where do tax rates come from?
Shipped in params.ts for New Zealand: social 0.016, VAT/GST 0.15, 5 brackets.
How should I verify this result?
May differ from payslip: KiwiSaver and student loan not fully entered. Cross-check with New Zealand authority notes: IRD — PAYE educational model.. Educational only.
What to calculate next
Sources & limits
Educational model for New Zealand. IRD — PAYE educational model. Not a substitute for payroll software or bank underwriting.