How do I calculate a percentage increase?

Subtract the old value from the new value, divide by the old value, then multiply by 100. For example, going from 50 to 60 is (60 minus 50) divided by 50, times 100, which is a 20% increase.

What is the difference between percentage increase and percentage change?

They use the same formula. Percentage increase describes a rise from old to new, while percentage change covers both rises and falls. If the new value is lower than the old value, the change is negative, which is a percentage decrease.

How do I increase a number by a percentage?

Multiply the number by 1 plus the percentage as a decimal. To increase 200 by 15%, multiply 200 by 1.15, which is 230.

Percentage Increase Calculator

This calculator works out the percentage increase between any two numbers, whether that is a price rise, a pay increase, a rent review, or growth in sales, visitors or any other measure between two periods. You enter two figures: the original (old) value and the new value. The calculator instantly returns the percentage increase, shown as a large percentage figure, along with a plain-English summary of the actual amount the value has risen by and the two figures you compared. It updates live as you type, so you can test different scenarios without pressing a button. If you enter a new value that is lower than the original, the calculator switches automatically to show a percentage decrease instead, so the same tool works for falls as well as rises. Underneath the calculator you will find the formula it uses (new minus old, divided by old, multiplied by 100), a worked New Zealand example using a weekly rent rise, and a separate explanation of how to increase a number by a percentage if you already know the percentage and need to work forward to a new figure. Use this tool whenever you need to express a change as a clear percentage figure, for pay negotiations, comparing quotes, tracking business growth or checking how much a bill or rent has actually gone up.

Calculate.co.nz is proud to be partnered with Health Based Building, a leader in sustainable and health-conscious building innovation. With over a century of experience, they develop high-performance systems like Foreverbreathe Specification, Magnum Board, and Foreverbreathe Paints to support energy-efficient, non-toxic living environments. Their commitment to healthier homes aligns with our belief that informed choices lead to better outcomes for Kiwi households.

Calculate.co.nz partner: Health Based Building

Original value

New value

20% increase

An increase of 10 (from 50 to 60)

If the new value is lower than the original, the result is shown as a percentage decrease.

How to calculate a percentage increase

Subtract the original value from the new value to get the change, divide that change by the original value, then multiply by 100. In short, percentage increase equals (new minus old), divided by old, times 100.

Worked New Zealand example

A weekly rent rises from $500 to $540. The change is $40. Divide $40 by the original $500 to get 0.08, then multiply by 100. That is an 8% increase.

To go the other way and increase $500 by 8%, multiply $500 by 1.08, which gives $540.

Increase a number by a percentage

To increase a value by a percentage, multiply it by 1 plus the percentage as a decimal. For example, to add a 15% margin to a $200 cost, multiply $200 by 1.15 to get $230.

Frequently asked questions

Percentage increase or percentage change?

They use the same formula. Percentage change covers both rises and falls, so a negative result is a percentage decrease.

Why divide by the original value?

Because a percentage increase is always measured against the starting point. The same $10 rise is a bigger percentage when the starting value is small.

Related calculators

Percentage Calculator: general percentage change between two numbers.
Percentage Difference Calculator: difference between two values as a percentage.
Percentage of a Percentage Calculator: take a percentage of a percentage.
Pay Rise Calculator: work out a pay increase.

If you've found a bug, or would like to contact us, or learn more about James Graham and Calculate.co.nz.

Calculate.co.nz is partnered with Interest.co.nz for New Zealand's highest quality calculators and financial analysis.

Calculate.co.nz is the sister site of CalculatorHub.com, the world's largest calculator website by tool count.

All calculators and tools are provided for educational and indicative purposes only and do not constitute financial advice.

Calculate.co.nz is proudly part of the Realtor.co.nz group, New Zealand's leading property transaction literacy platform, helping Kiwis understand the home buying and selling process from start to finish. Whether you're a first home buyer navigating your first property purchase, an investor evaluating your next acquisition, or a homeowner planning to sell, Realtor.co.nz provides clear, independent, and trustworthy guidance on every step of the New Zealand property transaction journey.

Calculate.co.nz is also partnered with Health Based Building and Premium Homes to promote informed choices that lead to better long-term outcomes for Kiwi households.

Calculate.co.nz is hosted in Auckland via SiteHost new Zealand.

All content on this website, including calculators, tools, source code, and design, is protected under the Copyright Act 1994 (New Zealand). No part of this site may be reproduced, copied, distributed, stored, or used in any form without prior written permission from the owner.

About & trust: Why Calculate is NZ's most comprehensive · By the Numbers · How we compare · Editorial standards · How we keep data current · NZ finance glossary · Research & data · Financial literacy NZ · About · Privacy policy · Terms of use

Reviewed and maintained. Last reviewed 2026-07-02 and checked on a twice-monthly cycle against IRD, RBNZ and Stats NZ. How we keep data current.