Percentage Calculator
Calculate a percentage of a number, find a percentage change, compare two values or work out a discount. See the formula alongside the answer.
Free · No signup · No watermark · On-device processing
Choose a calculation
How to calculate a percentage
- Choose the calculation you need.
- Enter the two labelled values.
- Calculate and review the answer and formula.
- Change the mode to try another calculation.
Percentage change and difference are different calculations
Percentage change compares a new value with a starting value: (new − original) ÷ original × 100. A starting value of zero does not define a percentage change. For clarity this calculator requires a positive starting value in that mode.
Percentage difference compares two non-negative values symmetrically using their average as the denominator. It is not the same as a change from one value to another. Both values being zero makes the average zero, so that case has no defined percentage-difference result.
Discount mode subtracts the chosen percentage from the starting amount and shows the saving. It accepts discounts from 0 to 100 percent. Results are rounded for display using ordinary floating-point arithmetic; they are not a replacement for a business’s accounting and rounding rules.
Privacy and browser support
Your input is handled in this browser tab. Selected files and entered text are not sent to Varento Tools by this tool. Some specialized libraries load only when needed. A browser with JavaScript and sufficient device memory is required. Read our local-processing explanation.
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Frequently asked questions
Is this tool free without daily usage limits?
Yes. Varento Tools has no signup, accounts, usage-count caps, paywalls or watermarks. Device memory, format support and browser restrictions can still limit technically demanding files.
What is 20% of 150?
20 ÷ 100 × 150 = 30.
What is the change from 80 to 100?
(100 − 80) ÷ 80 × 100 = 25%, an increase.
Why can’t a change start at zero?
Its formula divides by the starting value. Division by zero does not give a finite percentage change.
Does a 20% discount mean paying 20%?
No. It means saving 20% and paying the remaining 80%.