Back to Tools & Converters

Loan Comparison Calculator

Compare up to four loans side by side — interest rates, fees, repayments, and total cost of borrowing. Make an informed decision before signing up.

By Konstantin IakovlevPublished 28 March 2026Last reviewed
Data stays on your deviceVerified formula

About this calculator

This calculator uses loan comparison methodology (APR). Reference: Standard APR formula. Last consulted 20 March 2026.

What to compare beyond the rate

General principles 2026
  • Headline interest rate: Don't compare alone!
  • Establishment fee: $0–$500
  • Monthly admin fee: $0–$15
  • Early repayment fee: Varies (some $0, some 1-2%)
  • APR (true rate inc fees): Lender MUST disclose under CCCFA
  • Total cost over life: Best single comparison metric

Source: ComCom — Credit

Disclaimer

This calculator provides estimates for general information purposes only. Results are based on standard formulas and may not reflect your individual circumstances. Always consult a qualified professional for advice specific to your situation.

How to compare loan offers

Two loans at the same rate can differ in total cost if terms, fees, or compounding differ. Compare total cost, not just rate or monthly payment.

  1. 1

    Calculate PMT for each loan

    PMT = principal × i × (1+i)^n ÷ ((1+i)^n − 1)

    Same formula, different inputs.

  2. 2

    Total cost over loan life

    Total_cost = PMT × n + setup_fees + admin_fees

    Setup fees ($200-500) and monthly admin fees ($5-15) add up.

  3. 3

    Compare APR (true cost)

    APR = annualised rate including all fees

    APR > headline rate when fees are high. Demand APR disclosure.

Worked example

Inputs: Loan A: 10% / 5yr / no fees. Loan B: 9.5% / 5yr / $300 setup + $10/mo admin

Result: Loan A total: $19,135. Loan B total: $19,025 — only $110 saving despite lower rate.

Frequently Asked Questions

How do I compare loans in NZ?
When comparing loans in New Zealand, the most important step is to look beyond the advertised interest rate and focus on the total cost of the loan over its full term. Gather quotes from multiple lenders — banks, credit unions, and non-bank lenders — and request a breakdown that includes the interest rate, all fees (establishment, monthly, early repayment), and the total repayment amount. Use the annual percentage rate (APR) or comparison rate, which incorporates fees into a single figure, to make a like-for-like comparison. Online loan comparison tools and the sorted.org.nz calculator can help. Also consider loan flexibility: can you make extra repayments? Is there a redraw facility? Factor in any break fees for fixed-rate loans. The Credit Contracts and Consumer Finance Act (CCCFA) requires NZ lenders to disclose all costs upfront. Source: Commerce Commission NZ; sorted.org.nz.
How does a comparison rate help me pick the right loan?
A comparison rate (sometimes called an APR or annual percentage rate) is a standardised interest rate that combines a loan's headline interest rate with most of its fees and charges, expressed as a single annual percentage. This makes it easier to compare the true cost of loans from different lenders on a like-for-like basis. For example, a loan advertised at 8.5% with high establishment fees might have a comparison rate of 10.2%, while a loan at 9% with no fees might have a comparison rate of 9%. The higher the fees, the bigger the gap between the nominal rate and the comparison rate. In New Zealand, the CCCFA requires lenders to disclose the total cost of credit, though "comparison rate" as a specific term is more commonly used in Australia. Always ask your NZ lender for the total interest payable and total repayment amount over the loan term. Source: Commerce Commission NZ — CCCFA; sorted.org.nz.
Should I choose a shorter or longer loan term?
Choosing between a shorter or longer loan term in New Zealand involves a trade-off between monthly affordability and total interest paid. A shorter loan term means higher monthly repayments but significantly less total interest over the life of the loan. A longer term reduces monthly repayments, making the loan more manageable week to week, but dramatically increases the total amount you repay. For example, a $20,000 personal loan at 12% over 3 years costs about $6,640 in total interest and repayments of $664/month; the same loan over 7 years costs about $16,200 in total interest but only $431/month. If you can comfortably afford the higher repayments, a shorter term is almost always the better financial choice. Use a loan comparison calculator to model different scenarios before committing. Source: sorted.org.nz — Loan Calculator.
What is the total interest cost over a loan's life?
The total interest cost over a loan's life is the sum of all interest payments you make from the first repayment to the last — the difference between the total amount repaid and the original principal borrowed. This figure is the most important number when comparing loans, far more meaningful than the monthly repayment alone. For example, a $30,000 car loan at 10.95% over 5 years has monthly repayments of about $649, but the total interest paid is approximately $8,940 — nearly 30% of the original loan amount. To reduce total interest paid, consider making extra repayments when possible, choosing a shorter term if affordable, and selecting the lowest rate available for your risk profile. New Zealand lenders are required under the CCCFA to disclose the total cost of credit in the loan agreement before you sign. Always ask for this figure and factor it into your comparison. Source: Commerce Commission NZ — CCCFA.

Compares two or more loan options side-by-side — different rates, terms, or loan amounts — to find the cheapest total cost over the full term.

How this calculator works

For each option: monthly payment = P × (r(1+r)^n) / ((1+r)^n − 1). Total cost = monthly payment × n. Total interest = total cost − principal. Lower monthly payments from longer terms usually mean higher total interest.

Loan Comparison Key Facts

1% rate difference on $400k 25yr mortgage~$80,000 difference in total interest
Shorter term effectHigher monthly payments but lower total interest
Revolving creditCan reduce interest if balance actively managed

Always compare total cost of credit, not just monthly payments. Longer terms can significantly increase total interest paid.

Worked Examples

$400,000 mortgage: 7.0% over 25 years vs 6.5% over 25 years

At 7%: $2,828/month, total interest $448,400. At 6.5%: $2,706/month, total interest $411,800. Saving: $36,600 over the term.

  1. Option A: $400,000 at 7.0% for 25 years (300 months)
  2. Monthly rate: 7% / 12 = 0.5833%
  3. Monthly payment: $400,000 × (0.005833 × 1.005833^300) / (1.005833^300 - 1) = $2,828
  4. Total repaid: $2,828 × 300 = $848,400
  5. Total interest: $848,400 - $400,000 = $448,400
  6. Option B: $400,000 at 6.5% for 25 years
  7. Monthly rate: 6.5% / 12 = 0.5417%
  8. Monthly payment ≈ $2,706
  9. Total repaid: $2,706 × 300 = $811,800
  10. Total interest: $811,800 - $400,000 = $411,800
  11. Interest saving by choosing 6.5%: $448,400 - $411,800 = $36,600

Built and maintained by Konstantin Iakovlev. Data sourced from the IRD and official New Zealand government sources.

Last reviewed: