How to Calculate NZ Student Loan Repayments: Step-by-Step Guide

Welcome to Your NZ Student Loan Guide!

Hey there! If you have a New Zealand student loan and have started working, you might notice money being deducted from your pay packet under the 'SL' tax code. Understanding how these deductions are calculated doesn't require a degree in mathematics!

In New Zealand, if you earn over a certain limit (called the repayment threshold), you are required to pay back 12% of every dollar you earn over that threshold toward your student loan.

This guide will walk you through how to calculate your repayments by hand. Mastering this calculation will help you budget better, plan your financial future, and ensure your payroll deductions are accurate.

Prerequisites: What You Need Before You Start

Before we jump into the math, make sure you have the following pieces of information ready:

1. Your Gross Income: This is your total pay before tax, KiwiSaver, or any other deductions are taken out. You can find this on your payslip or employment contract.
2. Your Pay Frequency: Do you get paid weekly, fortnightly, monthly, or annually?
3. The Current Repayment Threshold: Inland Revenue (IRD) sets this threshold annually. For the tax year starting 1 April 2024, the annual threshold is $24,128.

Repayment Thresholds by Pay Frequency (2024/2025):

• Weekly: $464.00
• Fortnightly: $928.00
• Four-Weekly: $1,856.00
• Monthly: $2,010.66
• Annually: $24,128.00

The Underlying Formula

The calculation is straightforward. If your income for the pay period is less than or equal to the threshold, you pay $0. If your income is more than the threshold, use this formula:

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In simple terms: Subtract the threshold from your gross pay, then multiply the leftover amount by 12% (or 0.12).

Worked Example: Sarah's Fortnightly Pay

Let's put this into practice with a realistic example.

Meet Sarah. She works as a graphic designer in Wellington and earns a gross salary of $65,000 per year. She is paid fortnightly.

Step 1: Find Sarah's Gross Fortnightly Income

First, we divide her annual salary by the 26 fortnights in a year: �KBLK1�

Step 2: Identify the Fortnightly Threshold

Looking at our threshold list, the fortnightly repayment threshold is $928.00.

Step 3: Calculate Income Above the Threshold

Next, we subtract the threshold from Sarah's fortnightly gross income: �KBLK2� Sarah has $1,572.00 of "liable income" this fortnight.

Step 4: Calculate the 12% Repayment

Now, we multiply her liable income by 12% (or 0.12): �KBLK3�

Result: Sarah will have $188.64 deducted from her fortnightly pay to go toward her student loan.

Common Pitfalls to Avoid

• Using Net Income: Always use your gross income (before tax) for this calculation. Using your take-home pay will result in an underestimation of your repayments.
• Forgetting Secondary Tax Codes: If you have a second job, you don't get the threshold exemption on that second job. You must pay a flat 12% on all earnings from your secondary job if you use an 'SL' secondary tax code (like SB SL or S SL).
• Assuming Repayments Stop Automatically: When you make your very last payment, the IRD does not automatically notify your employer immediately. Keep an eye on your balance via myIR, and notify your employer to change your tax code back (e.g., from M SL to M) once it is fully paid off to avoid overpaying!

When to Use an Online Calculator

While doing the math by hand is great for understanding how your money is divided, using a free online NZ student loan calculator is highly recommended when:

• You receive a one-off bonus or commission, which can temporarily spike your pay cycle threshold.
• You have irregular hours or work multiple part-time jobs.
• You want to calculate voluntary extra payments to see how much faster you can become debt-free!