Percentage Calculator

How it works

1. Choose the calculation mode. 2. Enter values. 3. Click Calculate. 4. Read the result.

When to use it

The percentage calculator is useful in many everyday and professional situations:

• Shopping: calculate discounts, markdowns and final prices during sales or promotions.
• Personal finance: calculate investment returns, portfolio percentage changes.
• Work: prepare reports with percentage changes, calculate salary increases or profit margins.
• School & university: solve math problems with percentages, calculate weighted averages.
• Nutrition: calculate the percentage of macronutrients in your daily diet.

Advantages

4 calculation modes. Instant results. Free and no registration needed.

Benefits vs alternatives

Compared to traditional calculators or spreadsheets, our tool offers:

• 4 calculation modes: percentage of a value, increase, decrease and percentage difference in one tool.
• Instant results: no need to remember formulas or set up Excel cells.
• Accessible anywhere: works on any device with a browser, no app installation needed.
• 100% free: no usage limits, no invasive ads, no registration.
• Clear interface: designed for non-math experts, with results explained simply.

Common mistakes to avoid

1. Confusing increase and decrease: a 20% increase on 100 gives 120, but a 20% decrease on 120 gives 96, not 100. Percentages are not symmetrical.
2. Calculating percentage difference backwards: the difference between 50 and 75 is +50%, not +25%. It depends on which value is the base.
3. Forgetting the calculation base: "20% discount" and "20% margin" are different things. Always verify which amount the percentage is calculated on.
4. Cumulative rounding: in calculations with multiple successive percentages, rounding at each step introduces growing errors.
5. Percentages on percentages: a 10% increase followed by another 10% is not a 20% increase, but 21%.

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