Search

Percent Calculator NZ: Three Calculations on One Screen

Use our Percent Calculator with three modes on one screen - find a percentage of an amount, work out a proportion, or calculate the change between two numbers.
Updated 3 May 2026

Overview
  • Percentages are everywhere in personal finance. Working out the GST on a quote, the deposit on a property purchase, your KiwiSaver employer contribution, the proportion of your income going to housing, or the percentage your salary just rose by, are all the same arithmetic operation in slightly different forms.
  • Our Percent Calculator handles all three on a single screen so you don't have to convert between calculator types.

How to Use Our Percent Calculator

The calculator shows three modes simultaneously. Type into any sentence and the answer updates instantly:
  1. Find a percentage of an amount: Use this when you know a percentage, and you want to know what it equals in dollars (or any unit). Example: 15% of $200 is $30. This is the right mode for working out GST or making a deposit.
  2. Express one number as a percentage of another: Use this when you have two numbers and want to know what proportion one is of the other. Example: $30 is 15% of $200. This is the right mode for working out what share of your income goes to a particular category, or what proportion a deposit represents.
  3. Calculate the percentage change between two numbers: Use this when you have a starting number and an ending number, and you want to know how much it grew or shrank. An example is from $50,000 to $53,500 is a 7% increase. This is the right mode for salary raises, investment returns, price changes, and rate movements.

Important: Click any of the quick example chips at the bottom to load a common scenario, such as "GST on $100" or "20% deposit on $850,000."

Percent Calculator

Three percent calculations, all on one screen. Type into any sentence below to see the answer instantly.

1 Find a percentage of an amount
What is % of = 30
Useful for: GST on a price, tip on a bill, deposit on a property purchase, KiwiSaver employer contribution.
2 Express one number as a percentage of another
is what % of = 15%
Useful for: working out what proportion of your income goes to housing, what share a deposit represents, or what proportion of a portfolio one holding makes up.
3 Calculate the percentage change between two numbers
From to = 7%
an increase
Useful for: a salary raise, a price change, an investment return, the difference between two quotes, or how much a rate has moved.
Try a quick example:

Three things worth knowing about percentages

  1. Percentage points and percentages are not the same thing: When the OCR moves from 5% to 5.25%, that's a 0.25 percentage-point increase, but a 5% increase. The distinction matters in financial reporting and rate comparisons. If you're confused by a news headline saying "interest rates rose 25 basis points," that's the same as 0.25 percentage points, which is a different number from a 25% increase. Our basis points calculator explains more.
  2. A percentage decrease followed by an equivalent percentage increase doesn't return to the original number: If a $100 share drops 50% to $50, then gains 50% back, it ends at $75, not $100. This is why investment returns over volatile periods are often worse than the headline numbers suggest, and it's why long-term compound returns matter more than short-term percentage spikes.
  3. Percentages without context can be misleading: "Investment X returned 200%" sounds spectacular, but on a $100 investment that's only $200 in profit. A 5% return on $1,000,000 is $50,000. Always anchor a percentage to the underlying dollar amount before drawing any conclusions.
Other useful calculators