Helping Children Buy Calculator NZ

This calculator shows what happens when you help a child buy their first home by gifting or lending money toward their deposit, both for their borrowing power and for your own finances. You enter the property price, how much deposit your child has already saved, the amount you are gifting or lending, and the buffer you want to keep for yourself after helping. It adds your child's savings to your contribution to work out their total deposit and the deposit as a percentage of the price, then shows the loan they would still need and the resulting loan-to-value ratio, since a lower ratio generally means easier approval and a better interest rate. It also displays a note confirming the buffer you have left, as a reminder to check that is enough for your own retirement and emergencies before committing funds. Use it to see how a proposed gift or loan shifts your child from, say, a 10 percent deposit toward the 20 percent mark that often unlocks standard lending terms, and to weigh that benefit against what it leaves in your own accounts. It is worth deciding early whether the money is a gift or a loan, and documenting either choice in writing, particularly for larger amounts. This is an indicative estimate only, so get independent financial and legal advice before gifting or lending a significant sum toward a deposit.

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84%
your child's loan-to-value ratio with your help
Total deposit$110,000
Deposit percentage15.7%
Loan needed$590,000

After giving, you keep a buffer of $100,000. Make sure that is enough for your own retirement and emergencies before helping.

A bigger deposit lowers the loan-to-value ratio, which can mean easier approval and a better rate. If it is a loan rather than a gift, document it. Keep enough buffer for your own retirement and emergencies. Estimate only, get advice for large amounts.

How it works

The calculator adds your child's own deposit and your contribution to find the total deposit, then shows it as a percentage of the price and the loan they would need. It works out the loan-to-value ratio, which is the loan as a percentage of the price; a lower ratio generally means easier lending and a better rate. It also reminds you to keep a buffer for your own needs, since helping should not jeopardise your retirement.

Worked example

On a $700,000 home, a child with $50,000 plus a $60,000 gift has a $110,000 deposit, about 16%, needing a $590,000 loan at an 84% loan-to-value ratio. The gift moves them closer to a 20% deposit, which can unlock better lending, while you keep a $100,000 buffer for yourself.

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