Percentage Calculator — Calculate Percentages, Increases & Discounts

Use this Percentage Calculator to quickly calculate percentages, percentage increase, percentage decrease, discounts, markups, and percentage change between two numbers.
Percentages are used in everyday life for shopping discounts, taxes, tips, business reports, school grades, finance, sales growth, statistics, and general comparisons. This tool helps you calculate common percentage questions without doing the math manually.

What is % of ?
Formula
result = (% ÷ 100) × value

How to Use This Percentage Calculator

To calculate a percentage:

  1. Choose the percentage calculation type you need.
  2. Enter the required numbers.
  3. Click calculate.
  4. Review the result.
  5. Adjust the numbers if you want to compare different scenarios.

Depending on how the tool is built, it may help answer questions such as:

  • What is 20% of 150?
  • 45 is what percent of 300?
  • What is the percentage increase from 80 to 100?
  • What is the percentage decrease from 250 to 200?
  • What is the final price after a 30% discount?
  • What is the original price before a discount?
  • What is the markup percentage?
  • What is the percentage difference between two values?

What Is a Percentage?

A percentage is a way of expressing a number as a part of 100.

The word “percent” means “per hundred.” For example, 25% means 25 out of 100, or one quarter of the whole.

Percentages make it easier to compare values, even when the original numbers are different.

For example:

  • 50% means half.
  • 25% means one quarter.
  • 10% means one tenth.
  • 100% means the full amount.
  • 200% means twice the original amount.

Common Percentage Formulas

Different percentage questions use different formulas.

What is X% of Y?

Use this when you want to find a percentage of a number.

Formula:

Result = (Percentage ÷ 100) × Number

Example:

20% of 150 = 30

X is what percent of Y?

Use this when you want to know what percentage one number is of another number.

Formula:

Percentage = (Part ÷ Whole) × 100

Example:

45 is 15% of 300

Percentage Increase

Use this when a number goes up and you want to know the increase as a percentage.

Formula:

Percentage Increase = ((New Value - Old Value) ÷ Old Value) × 100

Example:

From 80 to 100 = 25% increase

Percentage Decrease

Use this when a number goes down and you want to know the decrease as a percentage.

Formula:

Percentage Decrease = ((Old Value - New Value) ÷ Old Value) × 100

Example:

From 250 to 200 = 20% decrease

Percentage Change

Percentage change measures how much a value increased or decreased compared with the original value.

Formula:

Percentage Change = ((New Value - Old Value) ÷ Old Value) × 100

A positive result means the value increased. A negative result means the value decreased.

What Can You Calculate With This Tool?

Depending on the calculator options, this percentage calculator can help with several common calculations.

Percent of a Number

Find a specific percentage of a number, such as:

  • 15% of 200
  • 8% of 750
  • 25% of 1,200

This is useful for discounts, tips, commissions, taxes, and portions.

Percentage of a Total

Find what percent one value represents out of a total.

For example:

  • 30 out of 50
  • 75 out of 100
  • 18 out of 60

This is useful for grades, survey results, completion rates, and performance comparisons.

Percentage Increase

Calculate how much a number increased compared with the original value.

For example:

  • Sales increased from 1,000 to 1,250.
  • Website visits increased from 5,000 to 7,500.
  • A price increased from $40 to $50.

Percentage Decrease

Calculate how much a number decreased compared with the original value.

For example:

  • A price dropped from $100 to $80.
  • Expenses decreased from $2,500 to $2,000.
  • Weight changed from 90 kg to 85 kg.

Discount Percentage

Calculate the amount saved and the final price after a discount.

For example:

  • 20% off $150
  • 35% off $80
  • 10% off $45

Markup Percentage

Calculate how much a price increased from cost to selling price.

For example:

  • Cost: $50
  • Selling price: $75
  • Markup: 50%

Example: Calculate 20% of 150

To calculate 20% of 150:

20 ÷ 100 = 0.20
0.20 × 150 = 30

So, 20% of 150 is 30.

This type of calculation is useful for finding tips, discounts, tax amounts, and partial values.

Example: Calculate a Discount

Suppose an item costs $120 and has a 25% discount.

First, calculate the discount amount:

25% of 120 = 30

Then subtract the discount from the original price:

120 - 30 = 90

The final price is $90 before any additional taxes or fees.

Example: Calculate Percentage Increase

Suppose a value increases from 200 to 260.

The increase is:

260 - 200 = 60

Then calculate the increase compared with the original value:

60 ÷ 200 × 100 = 30%

So, the value increased by 30%.

Example: Calculate Percentage Decrease

Suppose a value decreases from 500 to 400.

The decrease is:

500 - 400 = 100

Then calculate the decrease compared with the original value:

100 ÷ 500 × 100 = 20%

So, the value decreased by 20%.

Common Uses for a Percentage Calculator

You can use this calculator for:

  • Shopping discounts
  • Sales tax estimates
  • Tips at restaurants
  • School grades
  • Exam scores
  • Business growth
  • Revenue changes
  • Profit margins
  • Markups
  • Price increases
  • Price decreases
  • Fitness progress
  • Survey results
  • Website analytics
  • Conversion rates
  • Budget planning
  • Loan or interest comparisons
  • Everyday math problems

Percentages are used across many areas because they make comparisons easier to understand.

Percentage Calculator for Shopping

A percentage calculator is especially useful when shopping.

You can use it to calculate:

  • Discount amount
  • Final sale price
  • Tax amount
  • Tip amount
  • Price after markup
  • Price before discount
  • Savings compared with the original price

For example, if a store offers 30% off an item, this calculator can help you quickly estimate how much you save and what the final price may be.

Percentage Calculator for Business

Businesses use percentages to measure changes and compare performance.

Common business percentage calculations include:

  • Revenue growth
  • Cost reduction
  • Profit margin
  • Markup
  • Discount rate
  • Conversion rate
  • Customer growth
  • Churn rate
  • Completion rate

For example, if monthly revenue increases from $10,000 to $12,500, a percentage calculator can show the growth rate.

Percentage Calculator for School and Grades

Students and teachers often use percentages to calculate grades and scores.

For example:

  • 18 correct answers out of 20
  • 72 points out of 90
  • 45 marks out of 60
  • Final grade percentage
  • Assignment score percentage

A percentage calculator helps convert raw scores into percentage results quickly.

Percentage Calculator for Finance

Percentages are widely used in personal finance and financial planning.

You may use this calculator for:

  • Interest estimates
  • Investment returns
  • Budget percentages
  • Savings rates
  • Debt reduction
  • Income changes
  • Expense changes
  • Loan comparisons

This calculator is for general math and planning only. Financial decisions should be verified carefully and discussed with a qualified professional when needed.

Percentage Points vs. Percent Change

Percentage points and percent change are not the same thing.

Percentage Points

Percentage points measure the simple difference between two percentages.

Example:

An interest rate increases from 4% to 6%.
The increase is 2 percentage points.

Percent Change

Percent change compares the increase to the original value.

Example:

From 4% to 6% is a 50% increase.

This difference is important in finance, statistics, business reports, and news.

Tips for Accurate Percentage Calculations

For better results:

  • Enter numbers carefully.
  • Check whether you need percent increase or percent decrease.
  • Use the original value as the starting value for percentage change.
  • Remember that 50% off followed by another 50% off is not the same as 100% off.
  • Check whether tax, shipping, fees, or extra costs are included.
  • Round results only after the calculation when accuracy matters.

Small input mistakes can lead to very different percentage results.

Percentage Calculator FAQ

What is a percentage calculator?

A percentage calculator is an online tool that helps calculate percentages, percentage increase, percentage decrease, discounts, markups, and percentage change.

How do I calculate a percentage of a number?

Divide the percentage by 100, then multiply by the number. For example, 20% of 150 is 30.

How do I calculate what percent one number is of another?

Divide the part by the whole, then multiply by 100. For example, 45 out of 300 is 15%.

How do I calculate percentage increase?

Subtract the old value from the new value, divide by the old value, then multiply by 100.

How do I calculate percentage decrease?

Subtract the new value from the old value, divide by the old value, then multiply by 100.

What is the difference between percentage increase and percentage decrease?

Percentage increase measures how much a value went up compared with the original value. Percentage decrease measures how much a value went down compared with the original value.

Can I use this calculator for discounts?

Yes. Enter the original price and discount percentage to calculate the discount amount and final price.

Can I use this calculator for grades?

Yes. You can calculate a score percentage by dividing the points earned by the total possible points and multiplying by 100.

Can I use this for business calculations?

Yes. This calculator can help with general business math such as growth rates, markups, discounts, and conversion rates. Verify important business figures before using them in reports or decisions.

Does this calculator include tax or fees?

Only if the tool has fields for tax or fees. Otherwise, the result may not include additional costs.

Why is percent change based on the original value?

Percent change compares the amount of change to the starting value. This shows how large the change is relative to where it began.

Is this calculator financial advice?

No. This tool performs general percentage calculations. It does not provide financial, tax, legal, investment, or professional advice.

Important Limitations

This Percentage Calculator is designed for general math and convenience only.

It may not account for:

  • Taxes
  • Fees
  • Shipping costs
  • Discounts applied in multiple steps
  • Currency conversion
  • Rounding rules
  • Business accounting rules
  • Legal or tax requirements
  • Financial product terms
  • Statistical context

For important calculations, always verify the result and confirm the correct formula for your situation.

Disclaimer

This Percentage Calculator is provided for general informational and convenience purposes only. It should not be treated as financial, tax, legal, accounting, investment, educational, or professional advice.

For official reports, financial decisions, tax calculations, accounting records, legal documents, school policies, or business decisions, verify calculations with the relevant authority, qualified professional, or official formula.