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Home Renovation Loan Repayment Calculator

Updated 21 June 2026​
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Planning a renovation is exciting, but understanding the full cost of borrowing is what turns a dream project into an affordable one. Our calculator works out exactly what your renovation loan will cost each month and over the full loan term, so you can plan your budget with confidence before you commit.
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How to Use Our Home Renovation Loan Calculator
To work out what your renovation loan will cost, simply enter three details:
  1. The renovation loan amount. This is the total amount you want to borrow to fund your renovation, including materials, labour, and a contingency buffer for unexpected costs (most renovators end up spending 10% to 20% more than their initial budget).
  2. The loan term. This is how long you want to take to repay the loan. NZ renovation loans typically run 3 to 7 years for unsecured borrowing, and up to 25 to 30 years if the renovation is funded via a mortgage top-up.
  3. The interest rate. The rate you'll be offered depends on whether the loan is secured or unsecured, your credit profile, the loan amount, and current market conditions. Personal loan rates for renovations typically range from 7% to 16%, while mortgage top-up rates sit between 5% and 7%.

The calculator shows your repayment amount (weekly, fortnightly, or monthly), the total interest you'll pay, and the total cost of the loan including both principal and interest.

Important: A few important things to know about renovation loans
  • Advertised rates may not be the rates you'll actually be offered. Lenders display their best rates publicly, but those rates are typically reserved for borrowers with strong credit, lower loan amounts, or specific loan types. Always check what rate you would actually qualify for before committing to a renovation budget.
  • Renovation costs almost always exceed initial estimates. The most common pitfall NZ homeowners face is borrowing only the quoted amount and then needing top-up finance (often at higher rates) when costs blow out. Build a 15% to 20% buffer into your loan amount and the calculator's projections.
  • Consider your funding option carefully. A small renovation under $30,000 is often best funded through an unsecured personal loan, which is fast to arrange and doesn't put your home at risk if you can't repay. Larger renovations are usually cheaper over the loan term via a mortgage top-up, but the longer term means more interest paid in absolute dollars. Our Mortgage Calculator can help you model the mortgage top-up option for direct comparison.
  • Get fixed-price quotes before borrowing. Variable quotes are a recipe for cost overruns. Fixed-price contracts with NZ-licensed builders give you certainty about the total renovation spend, which lets you borrow the right amount the first time.

Renovation loan details

Repayment type
Standard repayment that pays off the loan balance over the term.
Payment frequency
Your monthly payment $0 Principal & Interest over 5 years
Renovation loan amount $0
Total interest $0
Total cost $0
Important: Our calculations are based on the assumption that you make the same fixed home renovation loan repayment for the entire loan period, the interest rate does not increase or decrease, you don't miss any repayment deadlines, overpay or underpay.

Video Explainer:
MoneyHub Founder Christopher Walsh explains how to use a home renovation loan calculator. He also compares your options - a one-off personal loan or withdrawing money on your mortgage. Both have unique pros and cons, specifically around the total cost of interest incurred during the life of the loan.
Christopher Walsh
MoneyHub Founder
Unlock the Best Personal Loan Rates with MoneyHub – Don't Overpay When Getting Personal Loan

Are you tired of overpaying with high interest rates and exorbitant fees? Our research shortlists three outstanding lenders known for their fair rates and reliable service:
Checking what interest rate you'll get is quick and easy - just a few minutes could save you thousands, given the range of interest rates. 

Remember, it's the interest rate you agree to now that makes a huge difference when you repay your loan week after week. We believe that signing up for finance with a car salesperson or via a bank is unlikely to be the cheapest option.

Advertising Disclosure: We may earn a commission from loans, but our top picks are always based on rigorous research and your best interest.

Home Renovation Loans Currently Available

Lenders include:

Enter your loan details

Repayment frequency
Important: Calculations use the standard amortisation formula and reflect the interest rate only. Establishment fees, monthly account fees, and other lender charges are not included and may apply on top of these figures. Interest rates shown are advertised rates and may vary based on your credit profile, the loan amount and other factors. Always confirm current rates and fees directly with the lender before applying.

What is the maximum limit for a renovation loan?

  • Renovation loans are usually limited to $50,000. 
  • Are you planning more extensive renovations, i.e. structural changes? If so, a home loan is more suitable; our guide covers the latest home loan offers.
  • If you already have a home loan, you can ask your bank about a home loan ‘top-up’. If approved, you can access a specific amount of money for your structural changes (i.e. an extension, a new roof, electrical wiring or plumbing, work on the foundations, wall removal, etc.). If you don’t repay the home loan, as is the case with any mortgage, the lender can repossess your home.

Where can I get the best home improvement loan deal?

  • Our guide to home improvement loans explains everything you need to know to make the right decision and has a list of best-buy finance deals (and alternatives that can fund more modest renovations). 
  • Know how to boost your credit score to get the best home renovation interest rate and bring down your overall renovation costs.
  • Our bathroom renovations guide explains must-know costs, how to get quotes, renovation facts and tips covers what matters.
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