% Percentage Tool

Free Online Percentage Calculator

Solve any percentage problem instantly — from basic calculations to percentage change, discount, markup, tip and more.

X% of Y X is what % of Y % Change % Increase / Decrease Discount Tip Calculator
📐 Formula: Result = (Percentage ÷ 100) × Number
% of = —
📐 Formula: Percentage = (Value ÷ Total) × 100
is what % of = —
📐 Formula: % Change = ((New − Old) ÷ Old) × 100
📐 Formula: New Value = Original × (1 ± Percentage/100)
📐 Formula: Final Price = Original × (1 − Discount/100)
📐 Formula: Tip = Bill × Tip% / 100  |  Per Person = Total ÷ People
✅
Result
—

What Is a Percentage Calculator and Why Use One?

A percentage is one of the most fundamental mathematical concepts used in everyday life, yet percentage calculations are also one of the most commonly misunderstood and error-prone areas of arithmetic. A percentage simply represents a fraction out of 100 — the word itself comes from the Latin "per centum," meaning "by the hundred." Whether you are calculating a discount at a shop, figuring out how much tip to leave at a restaurant, working out a pay rise, tracking your exam score, or analysing business growth, percentages are everywhere.

Our percentage calculator brings together six of the most commonly needed percentage tools in one place, each designed to give you instant, accurate answers along with the full working so you can understand exactly how the result was reached. No more mental arithmetic errors, no more confusion about whether to divide or multiply — just enter your numbers and get a clear answer in seconds.

This tool is especially useful for students checking their homework, shoppers comparing discounts, business owners calculating profit margins, employees working out tax or salary changes, and anyone who regularly works with financial data, statistics or academic grades. All six calculators run instantly in your browser without any need to install software or send data to a server.

🔢
X% of Y
Find the exact value that a percentage represents from any number.
❓
What % is X of Y
Find what percentage one number is of another instantly.
📈
% Change
Calculate percentage increase or decrease between two values.
⬆️
% Increase / Decrease
Apply any percentage increase or decrease to a starting value.
🏷️
Discount Calculator
Find the final price, savings amount and discount value instantly.
🍽️
Tip Calculator
Split the bill and calculate tip per person for any group size.

How to Use This Percentage Calculator

Each of the six calculator modes is designed to answer a specific type of percentage question. Here is a guide to each one along with real-world examples of when you would use it:

  1. 1
    X% of Y — Find a percentage of a numberUse this when you know the percentage and want to find the actual value. Example: "What is 15% of 2,400?" Enter 15 in the first box and 2,400 in the second. Useful for calculating tax, interest, commission, discounts or exam marks.
  2. 2
    What % is X of Y — Find the percentageUse this when you have two numbers and want to know the ratio as a percentage. Example: "45 is what percent of 180?" Enter 45 and 180 to find it is 25%. Perfect for calculating test scores, completion rates or market share.
  3. 3
    Percentage Change — Increase or decrease between two valuesEnter an original value and a new value to find out by what percentage it changed — and in which direction. Example: sales went from 800 to 1,040 — that is a 30% increase. Ideal for tracking growth, price changes or performance metrics.
  4. 4
    Percentage Increase / Decrease — Apply a % to a valueEnter a starting value and a percentage, then choose whether to increase or decrease. Example: increase a salary of £30,000 by 8% to get £32,400. Useful for salary negotiations, price adjustments or inflation calculations.
  5. 5
    Discount Calculator — Final price after discountEnter the original price and discount percentage to instantly see the final price, the amount saved, and what percentage of the original price you are paying. Add your currency symbol for a localised result.
  6. 6
    Tip Calculator — Split the bill fairlyEnter the bill amount, desired tip percentage, and number of people in your group. Get the tip amount, total bill with tip, and per-person share — so everyone pays exactly the right amount.

Real-World Uses for Percentage Calculations

Understanding and calculating percentages is a life skill that comes up constantly in both personal and professional contexts. Here are some of the most common real-world situations where a percentage calculator saves time and prevents costly mistakes:

  • Shopping and sales: Quickly work out how much you actually save on a 40% off sale, or compare two discount offers to find the better deal.
  • Tax calculations: Calculate VAT, sales tax, income tax brackets, or service charges on invoices and receipts with precision.
  • Salary and pay rises: Find out exactly how much a 5% or 10% pay rise adds to your annual or monthly salary before accepting an offer.
  • Academic grading: Convert raw scores to percentages, or find out how many more marks you need to reach a target grade.
  • Business profit margins: Calculate gross margin, markup percentage, or how a price increase affects profitability.
  • Financial investments: Track portfolio growth, calculate return on investment, or understand compound interest as a percentage gain.
  • Health and fitness: Calculate body fat percentage changes, macro ratios in your diet, or how close you are to a weight loss goal.
  • Restaurant and travel: Split bills fairly with the tip calculator, or calculate foreign exchange differences as percentage changes.
Frequently Asked Questions
The basic percentage formula is: Percentage = (Part ÷ Whole) × 100. To find a percentage of a number, use: Result = (Percentage ÷ 100) × Number. For percentage change: % Change = ((New Value − Old Value) ÷ Old Value) × 100. Each of our six calculator modes applies the correct formula automatically so you never need to remember them.
Percentage change can be either positive (an increase) or negative (a decrease). It always compares a new value to an original value. Percentage increase specifically refers to applying a positive percentage to make a value larger — for example, increasing a price by 15%. Our calculator handles both: the "% Change" mode tells you the direction and magnitude of change between two known values, while "% Increase/Decrease" applies a known percentage to a starting value.
To find the final price after a discount: Final Price = Original Price × (1 − Discount% ÷ 100). For example, a 30% discount on a Rs 2,000 item gives: 2,000 × 0.70 = Rs 1,400. The amount saved is Rs 600. Our discount calculator does all of this automatically and shows you the savings amount as well as the final price.
When dining out in a group, splitting the bill — including tip — can get complicated. Our tip calculator lets you enter the total bill, choose your tip percentage (typically 10–20%), and specify how many people are sharing. It instantly calculates the tip amount, the total bill including tip, and the exact per-person share so everyone pays fairly without any awkward mental arithmetic at the table.
To find the original price before a discount was applied, use: Original = Final Price ÷ (1 − Discount% ÷ 100). For example, if an item costs Rs 700 after a 30% discount, the original was: 700 ÷ 0.70 = Rs 1,000. You can use the "X% of Y" mode in reverse, or simply enter values into the discount calculator and adjust until the final price matches what you paid.
Yes — completely free with no registration required, and 100% private. Every calculation runs entirely within your browser using JavaScript. No numbers, values or any other data you enter are ever sent to a server or stored anywhere. You can use it as many times as you like without any tracking or data collection.
A percentage point is the arithmetic difference between two percentages. For example, if interest rates rise from 3% to 5%, that is a 2 percentage point increase. However, expressed as a percentage change, it is actually a 66.7% increase (because 2 ÷ 3 × 100 = 66.7%). This distinction matters in finance, economics and statistics where confusing the two can lead to significant misinterpretations of data.