Percentage Increase Calculator
Work out the percentage increase between two numbers, and see what the same rise looks like as a multiplier and as an absolute change.
The formula
% increase = (new − original) ÷ original × 100
Going from 80 to 100 is a 25% increase, because the 20-point rise is measured against the starting value of 80 — not against the finishing value. Dividing by the wrong number is the single most common mistake here, and it produces 20% instead of 25%.
Increasing a number by a percentage
To add 15% to 240, multiply by 1.15 rather than working out 15% and adding it. One step, no rounding in the middle: 240 × 1.15 = 276. The same shortcut runs backwards — to remove 15%, multiply by 0.85.
How to use the Percentage Increase Calculator
- Fill in each field with your own figures — the defaults are only there as an example.
- The result updates as you type, so there is no button to press.
- Check the breakdown under the main result for the supporting numbers.
- Use the copy button to take the result with you, or share the link to reload the same inputs.
Percentage Increase Calculator — frequently asked questions
What is the percentage increase from 80 to 100?
25%. The rise is 20, and 20 ÷ 80 = 0.25. Measuring against the original value is what makes it 25% rather than 20%.
How do I increase a number by a percentage?
Multiply by (1 + the percentage as a decimal). Adding 8% means multiplying by 1.08.
Is this percentage increase calculator free to use?
Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.
How accurate is the result?
The maths is exact for the formula shown on the page. Accuracy in the real world depends on your inputs and on assumptions the formula cannot see, so treat the output as a well-grounded estimate rather than a quote.
Can I use it on my phone?
Yes. The page is responsive, weighs a few kilobytes and works offline once loaded, so it behaves the same on a phone as on a desktop.
This page is a focused version of the Percentage Calculator, which handles every variation in one place.
What people search for
This page answers each of these searches. They are the exact phrases visitors use to find the percentage increase calculator.
- percentage increase formula
About this calculator
Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.
Last reviewed August 15, 2026 · Calculation runs client-side · No data collected · Report an error