Percentage Calculator

Percentages Are Everywhere — And Frequently Misunderstood

Percentages appear in almost every area of daily life — discounts, tax, salary increases, exam scores, interest rates, statistics, nutritional labels, and more. Most people learned how to calculate percentages in school and promptly forgot the mechanics as soon as they had a calculator available.

The problem is that there are several different types of percentage calculations, and mixing them up leads to wrong answers. "What is 15% of 80?" is a different calculation from "80 is 15% of what?" and both are different from "what percentage increase is it from 80 to 92?"

A percentage calculator handles all of these cases so you get the right answer without thinking through which formula applies.

How to Use the TakeTheTools Percentage Calculator

Open the Percentage Calculator on TakeTheTools.

The tool offers several calculation modes. Select the type of calculation you need:

What is X% of Y? — The most common calculation. Enter the percentage and the base number to find the result.

X is what percent of Y? — Find what percentage one number is of another.

Percentage change — Enter the original value and the new value to find the percentage increase or decrease between them.

X increased/decreased by Y% — Find the result after applying a percentage change to a number.

Enter your values and the result calculates instantly.

The Four Most Common Percentage Calculations

1. Finding a percentage of a number

Formula: Result = (Percentage ÷ 100) × Number

Example: What is 20% of 350? (20 ÷ 100) × 350 = 0.20 × 350 = 70

Use this for: calculating discounts, finding tax amounts, determining tips.

2. Finding what percentage one number is of another

Formula: Percentage = (Part ÷ Whole) × 100

Example: 45 is what percent of 180? (45 ÷ 180) × 100 = 0.25 × 100 = 25%

Use this for: calculating exam scores, finding what share one value represents of a total.

3. Calculating percentage increase

Formula: Percentage increase = ((New − Original) ÷ Original) × 100

Example: A salary increases from Rs 50,000 to Rs 58,000. What is the percentage increase? ((58,000 − 50,000) ÷ 50,000) × 100 = (8,000 ÷ 50,000) × 100 = 16%

Use this for: salary negotiations, price changes, growth calculations.

4. Calculating percentage decrease

Same formula as increase, but the result is negative when the new value is lower.

Example: A product price drops from Rs 2,400 to Rs 1,980. What is the percentage decrease? ((1,980 − 2,400) ÷ 2,400) × 100 = (−420 ÷ 2,400) × 100 = −17.5%

The product decreased in price by 17.5%.

Real-World Examples

Shopping discounts: A jacket is listed at Rs 8,500 with a 30% discount. What is the sale price? 30% of 8,500 = 2,550. Sale price = 8,500 − 2,550 = Rs 5,950

Sales tax: A laptop costs Rs 120,000 before 17% sales tax. What is the total? 17% of 120,000 = 20,400. Total = 120,000 + 20,400 = Rs 140,400

Exam score: You answered 43 out of 50 questions correctly. What is your percentage score? (43 ÷ 50) × 100 = 86%

Salary negotiation: Your current salary is Rs 80,000 and you want a 15% raise. What would your new salary be? 15% of 80,000 = 12,000. New salary = 80,000 + 12,000 = Rs 92,000

Investment return: You invested Rs 200,000 and it grew to Rs 247,000. What was your return percentage? ((247,000 − 200,000) ÷ 200,000) × 100 = 23.5%

A Common Mistake: Percentage Increase vs Percentage Points

These two concepts are frequently confused and the difference matters.

If an interest rate rises from 5% to 8%, it increased by 3 percentage points (the arithmetic difference between the two percentages).

But the percentage increase in the interest rate is: ((8 − 5) ÷ 5) × 100 = 60% (the rate itself increased by 60%).

Both statements are true and both are meaningful in different contexts. "The rate rose by 3 percentage points" and "the rate increased by 60%" describe the same change from different perspectives. Knowing which is being used matters when evaluating financial products, statistics, or economic claims.

Tip Calculation — The Quick Version

For restaurant tips, a fast mental shortcut:

10% tip: Move the decimal point one place left. Rs 1,850 → Rs 185 tip.

15% tip: Find 10%, then add half of that. Rs 185 + Rs 92.50 = Rs 277.50 tip.

20% tip: Find 10% and double it. Rs 185 × 2 = Rs 370 tip.

For exact calculations with any tip percentage, the TakeTheTools Percentage Calculator handles it instantly.

Disclaimer

All calculations provided by this tool are for informational and educational purposes only. They are not financial advice. For tax calculations, salary negotiations, loan decisions, or any consequential financial matter, consult a qualified professional.

Final Thoughts

Percentages are one of the most practically useful areas of mathematics and one of the easiest to get wrong when you are doing the calculation in your head or mixing up which formula to use. A dedicated calculator handles the arithmetic correctly every time.

The TakeTheTools Percentage Calculator covers all common percentage calculation types, updates instantly, runs in your browser, and is completely free.