Percentage Calculator

Calculated number: —

All 6 core tools. Built mobile-first for slow devices.

🧮Percent of a number

How much is (p)% of (x)?
→ Find part of something (tip, tax, savings).

📈Increase by a percentage

What is (x) plus (p)%?
→ Also asked as: “What is (p)% on top of (x)?”
→ Add a percentage (pay rise, price increase).

📉Decrease by a percentage

What is (x) minus (p)%?
→ Also asked as: “What is (p)% off (x)?”
→ Take off a percentage (discounts, offers).

🔄Percentage change

How much did the value change from (x) to (y)?
→ Did it go up or down, and by what percent?
→ Find how much something increased or decreased (price change, salary change, growth or loss).

📊Calculate percentage

(x) is what % of (y)?
→ Also asked as: “X out of Y is what %?”
→ Example: 50 out of 200 is what percent?

⏪Reverse % calculator (Original amount)

If (p)% was added or removed from the original amount (X) and the final amount is (y),
what was the original amount (X)?
→ Also asked as: After a (p)% increase or decrease from (X), the final amount is (y). What was the original amount (X)?
→ Find the price before tax, discount, or commission.

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Percentage Calculator – All 6 Core Calculations Explained (Updated 2026)

This percentage calculator helps you calculate percentage quickly and correctly.

It includes all 6 fundamental percentage calculations used in school, shopping, salary, finance, and business:

Whether you need a discount calculator, salary percentage calculator, percent increase calculator, or a percentage difference calculator, this page explains everything clearly.

1️⃣ About This Calculator

This is a complete percentage calculator online built for everyday use.

It combines all major percentage formulas into one simple page.

You can:

All formulas follow standard mathematical percentage formulas used globally in education and finance.

Updated: January 2026.

2️⃣ How To Use This Percentage Calculator

Step 1: Choose the type of percentage calculation you need.
Step 2: Enter your numbers.
Step 3: Click calculate.
Step 4: Review your answer instantly.

Each calculator includes:

No advanced math knowledge is required.

3️⃣ Who Should Use This?

This percentage calculator is useful for:

If you ever ask “What percent is this?” or “How much did it increase?”, this tool is for you.

4️⃣ Why This Calculator?

Many websites show only one percentage formula.

This calculator includes all 6 core percentage calculations in one place.

It does more than give answers.

It explains:

It is:

You don’t need advanced math skills. You only need your numbers.

5️⃣ What Is a Percentage?

A percentage means “out of 100.”

For example, 25% means 25 out of 100.

If 25 out of 50 students passed:

Step 1: 25 ÷ 50 = 0.5
Step 2: 0.5 × 100 = 50%

So 50% of students passed.

We use percentages to:

6️⃣ All Core Percentage Formulas

Percent of a Number

value = (p/100) × x

Example: 15% of 200

15 ÷ 100 = 0.15
0.15 × 200 = 30

Used for tax, tips, and interest calculations.

Increase by a Percentage

new value = x × (1 + p/100)

Example: 500 increased by 10%

10 ÷ 100 = 0.10
1 + 0.10 = 1.10
500 × 1.10 = 550

Used for salary raise percentage and growth percentage.

Decrease by a Percentage

new value = x × (1 − p/100)

Example: 500 decreased by 10%

10 ÷ 100 = 0.10
1 − 0.10 = 0.90
500 × 0.90 = 450

Used for discount calculator and percent off price calculations.

Calculate Percentage (One Number of Another)

percentage = (x/y) × 100

Example: 50 out of 200

50 ÷ 200 = 0.25
0.25 × 100 = 25%

Used to calculate percentage between two numbers.

Percentage Change

percent change = ((new − old) / old) × 100

Example: 100 to 120

120 − 100 = 20
20 ÷ 100 = 0.20
0.20 × 100 = 20%

Used for calculate growth percentage and salary increase percentage.

Reverse Percentage (Original Amount)

original = y / (1 ± p/100)

If percent was added → divide by (1 + decimal).
If percent was removed → divide by (1 − decimal).

Example: Final price 110 after 10% increase

110 ÷ 1.10 = 100

Used to find original price before tax, discount, or commission.

7️⃣ Explanation of Each Calculator

8️⃣ Best Practices When Using Percentages

9️⃣ Comparison Section

Percentage Change vs Percentage Difference

Percentage change compares a new value to its original value.

Percentage difference compares two numbers using their average.

percent difference = |x − y| / ((x + y)/2) × 100

Use percentage change for before-and-after situations.
Use percentage difference for comparing two independent values.

🔟 Frequently Asked Questions

1. How do I calculate percentage of a number?

To calculate the percentage of a number, divide the percentage by 100 and multiply it by the number.

value = (p/100) × x

Example: What is 20% of 150?

20 ÷ 100 = 0.20
0.20 × 150 = 30

So 20% of 150 is 30. This is the most common use of a percentage calculator. It is used for tips, tax, interest, and commission.

2. How do I calculate percentage increase?

To calculate percentage increase, compare the new value to the original value.

Step 1: Subtract old value from new value.
Step 2: Divide by the old value.
Step 3: Multiply by 100.

percent change = ((new − old) / old) × 100

Example: If a salary increases from 1000 to 1200:

1200 − 1000 = 200
200 ÷ 1000 = 0.20
0.20 × 100 = 20%

The salary increased by 20%. This is how a salary increase percentage calculator works.

3. How do I calculate percentage decrease?

To calculate percentage decrease, use the same formula as percentage increase, but the result will be negative.

percent change = ((new − old) / old) × 100

Example: If a price drops from 500 to 400:

400 − 500 = −100
−100 ÷ 500 = −0.20
−0.20 × 100 = −20%

The price decreased by 20%. This is often used in a discount calculator or percent off calculator.

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

To calculate percentage between two numbers, divide one number by the other and multiply by 100.

percentage = (x/y) × 100

Example: 50 out of 200:

50 ÷ 200 = 0.25
0.25 × 100 = 25%

So 50 is 25% of 200. This is sometimes called a percentage finder or calculate percentage tool.

5. What is the difference between percentage change and percentage difference?

Percentage change compares a new value to its original value.

Percentage difference compares two numbers using their average.

percent difference = |x − y| / ((x + y)/2) × 100

Use percentage change for before-and-after situations. Use percentage difference when comparing two separate values. Many people confuse these two formulas.

6. How do I calculate reverse percentage (original amount)?

If you know the final value after a percentage increase or decrease, divide by:

original = y / (1 ± p/100)

Example: Final price is 110 after a 10% increase:

10 ÷ 100 = 0.10
1 + 0.10 = 1.10
110 ÷ 1.10 = 100

The original price was 100. This is called a reverse percentage calculator.

7. How do I calculate discount percentage?

To calculate discount percentage:

Step 1: Subtract sale price from original price.
Step 2: Divide by original price.
Step 3: Multiply by 100.

Example: Original price 200, sale price 150:

200 − 150 = 50
50 ÷ 200 = 0.25
0.25 × 100 = 25%

The discount is 25%. This is how a discount percentage calculator works.

8. How do I calculate profit percentage?

Profit percentage compares profit to cost price.

Step 1: Subtract cost from selling price.
Step 2: Divide by cost price.
Step 3: Multiply by 100.

Example: Cost = 80, Selling price = 100:

100 − 80 = 20
20 ÷ 80 = 0.25
0.25 × 100 = 25%

Profit percentage is 25%. This is used in a profit percentage calculator.

9. Why do we divide by 100 in percentage calculations?

Because percent means “per hundred.” Dividing by 100 converts a percentage into decimal form. Decimals are needed before multiplying.

For example, 15% becomes 0.15 before multiplying. Without converting to decimal, the result will be wrong.

10. Can a 10% increase and 10% decrease cancel each other?

No. If a number increases by 10%, the base changes. If it then decreases by 10%, it decreases from the new number, not the original.

Example: 100 increased by 10% = 110, then 110 decreased by 10% = 99.

You end up with 99, not 100. This is a common mistake when using percent increase and decrease formulas.

Author & Review Information

This percentage calculator and guide was created and reviewed by a digital analytics and performance specialist with over 10 years of experience in data analysis and financial reporting.

All formulas follow standard mathematical percentage formulas taught globally and used in finance, business, and education.

Content reviewed and updated: January 2026.