Free Percentage Calculator
Calculate percentages instantly: what is X% of Y, percentage change, percentage difference, add or remove a percentage, find the original value. Six modes in one tool, with step-by-step explanations.
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6 modes: percentage of, what percent is, change, add/remove, find original
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Calculate profit margin for free →Frequently Asked Questions
How do I calculate a percentage of a number?
To calculate X% of Y, multiply Y by X and divide by 100. Example: 20% of 150 is 150 × 20 / 100 = 30. With this calculator, just enter the two numbers and the result appears in real time.
How do I calculate percentage change between two numbers?
Percentage change is calculated with the formula: ((new - old) / old) × 100. If the old value is 80 and the new is 100, the change is ((100 - 80) / 80) × 100 = +25%. A negative value indicates a decrease.
How do I add or remove a percentage from a number?
To add X% to Y: multiply Y × (1 + X/100). Example: adding 20% tax to $100 = $100 × 1.20 = $120. To remove: Y × (1 - X/100). Removing 10% from $200 = $200 × 0.90 = $180.
What is the difference between percentage and percentage points?
If a rate goes from 10% to 15%, it increased by 5 percentage points but by 50% in terms of relative percentage change. Percentage points indicate the absolute difference between two values expressed as percentages.
How do I find what percentage one number is of another?
To find what percentage X is of Y, divide X by Y and multiply by 100. Example: 30 is (30 / 150) × 100 = 20% of 150. This is useful for proportions, discounts, and market shares.
How do I find the original price before a discount?
If you know the discounted price and the discount percentage, use the formula: Original price = Discounted price / (1 - discount/100). Example: if the price after a 20% discount is $72, the original price was 72 / (1 - 0.20) = 72 / 0.80 = $90. Use the “Find Original” mode to calculate this automatically.
What is the difference between percentage change and percentage difference?
Percentage change measures how much a value increased or decreased from an original value: ((new - old) / old) × 100. Percentage difference compares two values without treating either as the baseline: |A - B| / ((A + B) / 2) × 100. Use percentage difference when neither value is the “starting point”.
How do I calculate percentages on a calculator?
On a standard calculator, to find 15% of 200 enter: 200 × 15 ÷ 100 = 30. With this online percentage calculator, just type two values and the result appears instantly, including the formula used and step-by-step explanation. No memorizing formulas required.
How do I calculate the percentage of a discount?
To find the discount percentage use the formula: ((Original price - Sale price) / Original price) × 100. Example: a product originally $80 sold for $60 has a discount of ((80 - 60) / 80) × 100 = 25%. Use the “What % is X of Y” mode to calculate it automatically.
How do I calculate percentage in Excel?
In Excel, to calculate 20% of cell A1 type the formula =A1*20%. For percentage change between A1 and B1: =(B1-A1)/A1. Format the cell as “Percentage”. Alternatively, use this online calculator for instant results without formulas.
Complete Guide to Percentage Calculations
The 6 essential percentage formulas
Percentage calculations are among the most common math operations in daily life, from comparing prices to calculating discounts, from tax computations to evaluating investments. Here are the six formulas that cover every scenario:
1. What is X% of Y — The most common. Formula: Y × X / 100. Example: 15% of 300 = 45. Use it for discounts, taxes, tips, commissions.
2. What percentage is X of Y — Formula: (X / Y) × 100. Example: 45 out of 300 = 15%. Useful for understanding proportions and shares.
3. Percentage change — Formula: ((new - old) / old) × 100. Example: from 200 to 250 = +25%. Essential for comparing prices, salaries, revenue over time.
4. Add percentage — Formula: Y × (1 + X/100). Example: $100 + 20% tax = $120. Indispensable for tax calculations and markups.
5. Remove percentage — Formula: Y × (1 - X/100). Example: $200 - 30% discount = $140. Used for discounts, reductions, depreciation.
6. Find original value — Reverse formula: result / (percentage / 100). Example: if $72 is 80% of the original price, the original was 72 / 0.80 = $90. Useful for finding the price before a discount was applied.
Percentages in business and finance
Percentages are the universal language of business. Profit margin is expressed as a percentage: a 30% margin on a $100 product means $30 profit. Revenue growth is measured as year-over-year percentage change. The conversion rate of an e-commerce store (visitors who buy) is a critical percentage for every entrepreneur. Even sales tax is a percentage: 20% in the UK, 19% in Germany, varying rates in the US.
Mastering percentage calculations means making better decisions: comparing offers, evaluating returns, negotiating discounts, and understanding financial reports without ambiguity.
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