Percentage Increase Calculator

How it works

Percentage increase measures how much a value has grown relative to its original amount. It is useful for comparing prices, salaries, populations, scores, and many other quantities over time.

The formula

You subtract the original from the new value to find the absolute change, divide by the original to express that change as a proportion, then multiply by 100 to convert it to a percentage.

Why this works: The numerator (New - Old) captures how much the value has grown in absolute terms. Dividing by the original value scales that growth relative to where you started. A salary rising from £28,000 to £30,000 is a much bigger deal proportionally for one person than another, and the percentage increase reflects that relative size correctly.

Related calculations

Use this calculator when a value has gone up and you want to express the growth as a percentage. To calculate a pay rise and see your new salary, there is a dedicated calculator for that. For a general comparison in either direction, you can see the overall change as a percentage. If the answer is negative, the value has fallen and you should use the tool that calculates the percentage drop.

Worked examples

When to use this

Percentage increase comes up in a wide range of UK financial and academic contexts. Here are four specific situations where it is especially useful:

• Tracking house price growth: The UK average house price rose from £232,000 in January 2020 to £285,000 in early 2025. That is a percentage increase of roughly 23%. Understanding this figure helps you gauge whether your own property has kept pace with the market.
• Comparing energy price cap changes: Ofgem raised the default unit rate significantly between 2021 and 2023. Expressing those rises as percentage increases makes it easier to compare annual changes and budget accordingly.
• Salary benchmarking: If a colleague in a similar role earned £34,000 and you earn £29,000, the percentage increase needed to reach their level is (5,000 / 29,000) x 100 = 17.2%. Knowing this number before a pay review puts your request in concrete terms.
• Investment returns: A stocks and shares ISA that grew from £8,000 to £10,400 has returned a 30% increase. Comparing this across different ISAs or time periods using consistent percentage terms makes performance meaningful.

Understanding the result

A percentage increase of 100% means the value has doubled. A 50% increase means it has grown by half as much again. Very large percentage increases, such as 300% or 400%, are common when comparing very small base values to larger new ones, for example when a niche investment grows from £200 to £1,000 (a 400% increase).

The percentage increase only tells you the relative size of the growth. A 10% rise on a £200,000 house adds £20,000, while a 10% rise on a £50,000 salary adds £5,000. The percentage is the same, but the real-world impact is very different. Always consider the absolute figures alongside the percentage to understand the full picture.

Related concepts

➡ To see how two rates differ in absolute terms rather than relative ones, you can measure the arithmetic gap between two rates in percentage points. ➡ If you want to find the exact pound amount that a percentage represents, the percentage of a number calculator gives the absolute figure. ➡ To recover the original figure before a percentage increase was applied, you can work backwards from an inflated total to find the starting value.

How to do this in Excel

Put the original value in cell A1 and the new value in cell B1. The formula subtracts the original from the new, divides by the original, and multiplies by 100 to return the percentage increase. If you want the result formatted as a percentage automatically, omit the *100 and apply a percentage number format to the cell instead.

How to do this without a calculator

Subtract the old value from the new to get the absolute change. Then estimate the percentage by dividing the change by the original and rounding mentally. For instance, if a bill goes from £80 to £96, the change is £16. Dividing 16 by 80 gives 0.2, which is 20%. For round numbers this is quick to do in your head. For awkward figures, break the original into easy fractions: if the original is £120, finding 10% is £12, so a £18 rise is 15%.

Real world uses

• Checking how much UK house prices have risen in your area over the past year.
• Calculating the percentage increase in a supermarket essential to track food inflation.
• Seeing how much your energy bill has gone up compared to the same month last year.
• Finding out the percentage rise in your council tax from one financial year to the next.
• Measuring how much an investment portfolio has grown since you first started contributing.

Common mistakes

Related calculators