What is a Percentage Calculator?

A Percentage Calculator is a free online tool that quickly solves any everyday percent problem in seconds. You can use it to find X% of a number, figure out what percent one number is out of a second number, and calculate percentage increase/decrease, discounts, tips, tax, and grades. It is suited for students, shoppers, and professionals who want a quick and easy way to get fast, accurate results without doing any math themselves or using spreadsheets.

How Does the Percentage Calculator Work?

• Percent of a number: enter the base (original value) and percent → get X% of the base.
• What percent is A of B? enter A and B → get (A ÷ B) × 100%.
• Increase/Decrease: enter Original and New → get % change and how much was added/removed.
• Reverse percent: enter Result and Percent → get the Original value.

Examples

• 20% of 150 = 30
• What percent is 45 of 60? → 75%
• Increase from 80 to 100 → +25% (change = 20)
• Decrease from 200 to 180 → −10% (change = −20)
• 45 is 15% of what? → 300

Formulas Used in Percentage Calculations

• X% of Y: (X ÷ 100) × Y
• What percent is A of B: (A ÷ B) × 100%
• % Increase: ((New − Original) ÷ Original) × 100%
• % Decrease: ((Original − New) ÷ Original) × 100%
• Reverse percent (find Original): Original = Result ÷ (Percent ÷ 100)

Key Benefits of Using This Percentage Calculator Online

• Fast and easy: takes the user confusion, manual errors, and repetitive math away.
• Integrated: it covers all scenarios such as percent of, percent change, reverse percent, and “A is what percent of B”.
• Convenient: Works perfectly for discounts, tax/tip, grades, KPIs, profit/markup, budgeting, etc.
• User-friendly: Clean inputs, instant outputs, and simple to copy.
• Works on any device: Excellent on mobile, tablet PC, or desktop.

Practical Example Use-Case

• Shopping discount: Store price of ₹1,999, discount of 25% → savings = ₹499.75 and final price = ₹1,499.25 (before tax). If tax is needed add 5% tax which would be show 1,574.21.
• Grades: Got 43/50 → equals 86%. Need >= 75% overall. The calculator will show how many points you need on the next test to reach that goal.
• Business KPI: Revenue increased from ₹80k to ₹100k → +25% growth. COGS decreased from ₹200k to ₹180k → −10% growth.