Percentage Calculator — 3 Ways to Calculate Percentages Free
Calculate percentages in three different ways
Three modes: What is X% of Y? X is what percent of Y? What is the percentage change from X to Y? Instant results.
About Percentage Calculator
Percentages express a value as a fraction of 100, making them a universal language for comparing proportions, changes, and ratios across disciplines. From calculating discounts and tax to analysing statistical data and financial returns, percentages appear in virtually every quantitative context.
This calculator provides three distinct modes to cover the most common percentage problems encountered in everyday life and professional settings. Rather than remembering which formula to apply, simply select the mode that matches your question and enter the two known values.
Mode 1 ("What is X% of Y?") handles discount calculations, tip calculations, tax calculations, and commission computations. Mode 2 ("X is what percent of Y?") determines what proportion one number is of another — useful for grading, market share analysis, and progress tracking. Mode 3 ("Percentage change") computes growth or decline between two values — essential for financial analysis, sales reporting, and scientific measurement comparisons.
Common real-world uses include calculating VAT or sales tax on purchases, determining discount savings during sales, computing exam score percentages, analysing month-over-month revenue changes, tracking fitness goal progress, and splitting expenses proportionally. All calculations are instant and performed in your browser.
Frequently Asked Questions
What are the three calculation modes?
Mode 1: "What is X% of Y?" — e.g. 15% of 200 = 30. Mode 2: "X is what percent of Y?" — e.g. 30 is what % of 200? = 15%. Mode 3: "Percentage change from X to Y" — e.g. from 200 to 240 = +20% increase.
How do I calculate a percentage decrease?
Use Mode 3. Enter the original value as X and the new (lower) value as Y. The result will be a negative percentage, indicating a decrease.
How do I calculate a tip using percentages?
Use Mode 1. Enter the tip percentage as X and the bill total as Y. The result is the tip amount. Add it to the bill for the total.
How is percentage change calculated?
Percentage change = ((New Value − Old Value) ÷ Old Value) × 100. A positive result indicates an increase; negative indicates a decrease.