Percentage Calculator
Three calculators in one: find X% of Y, find what percentage X is of Y, and calculate percentage increase or decrease between two values.
How percentages work
A percentage expresses a number as a fraction of 100. To find X% of Y, multiply Y by X ÷ 100. To find what % X is of Y, divide X by Y and multiply by 100. For percentage change between an old and new value, the formula is (New − Old) ÷ Old × 100.
For example, 20% of 150 is 30. And 30 is 20% of 150. A change from 150 to 180 is a 20% increase.
Common percentage uses
- Tips — calculate 15%, 18% or 20% of a bill
- Discounts — find the savings on a sale price
- Growth — measure revenue or user growth over time
- Commissions — calculate sales commission percentages
- Tax — percentage-based tax rates
What Does a Percentage Calculator Do?
A percentage calculator makes common percentage math easier. Find a percentage of an amount, compare two values, work out a percentage change, or just check a number before using it in a document.
Percentages show up everywhere in business — discounts, tax rates, commissions, growth comparisons, pricing.
What Goes Into a Percentage Calculation
- Base value: The number the percentage is calculated from.
- Percentage: The rate you're applying or comparing.
- Percentage amount: The result of applying the percentage to the base.
- Comparison values: You'll need two numbers for percentage increase or decrease.
- Direction: Are you adding, subtracting, comparing, or reversing a percentage?
- Rounding: Match the precision to whatever you need it for.
How to Use It
- Open the Percentage Calculator.
- Pick the type of calculation you need.
- Enter the values.
- Check the result and the direction.
- Use the number in your quote, invoice, report, or worksheet.
Frequently Asked Questions (FAQs)
1. What can a percentage calculator be used for?
Percentage-of calculations, comparisons, increases, decreases, and similar tasks.
2. Can I use it for discounts?
Yes — that's one of the basic steps for working out a discount.
3. Why can percentage changes look different from simple subtraction?
Because percentage change depends on a defined base value, so direction and starting point matter.
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