Need recurring invoices & client management? Need more than a free tool? Try Billora — Invoicing Software for Small Businesses Calculate percentages instantly — find X% of a number, percentage change, increase & decrease, discount prices, tip amounts, and markup. Free, no sign-up, works on any device. Basic Percentage Find percentage of a number Percentage Change Calculate increase or decrease Discount Calculator Calculate sale prices and savings Calculate tips and split bills Markup & Margin Calculate profit margins and markups No calculations yet How to Calculate Percentage Online Four simple steps — pick a mode, enter your values, and get an instant breakdown with full details. Choose a Calculator Mode Select the tab that matches your task — Basic , Change , Discount , Tip , or Markup . Enter Your Values Type your numbers into the input fields. All inputs support decimals . Use quick-preset buttons (5%, 10%, 20%…) to fill values instantly. Click Calculate Press Calculate or the → arrow next to any input row. Results appear instantly — no page reload required. Read the Full Breakdown The result panel shows the main answer plus supporting details — difference , multiplier , savings , or per-person split depending on the mode. Pro Tip: Use the Discount mode's quick-preset buttons to instantly apply common sale percentages — no typing needed. Switch between modes anytime without losing your entered values. 5 Powerful Percentage Calculators in One Everything from basic percent math to business markup — all free, all instant, no sign-up required. Basic Percentage Solve all three core problems: X% of Y , X is what % of Y , and X is Y% of what . Perfect for everyday math and homework. Percentage Change Calculate percentage increase or decrease between two values. Also increase or decrease any number by a given percentage. Discount Calculator Find the sale price and savings amount for any discount. Quick-preset buttons for 5%, 10%, 20%, 25%, and 50% off. Calculate tip amount and total bill for any percentage. Split the total across multiple people for easy group dining. Markup & Margin Calculate selling price , profit amount , and profit margin % from cost and markup. Essential for retail and business pricing. Fully responsive on all screen sizes. Results calculate instantly with no page reload. No account, no download, no ads blocking your work. How to Calculate Percentages — Formulas & Examples A percentage is a number expressed as a fraction of 100. The word comes from the Latin per centum , meaning "by the hundred." Percentages appear everywhere — from school grades and bank interest rates to shopping discounts and nutrition labels. Basic Percentage Formula The core formula is: Percentage = (Part ÷ Whole) × 100 . 30 students passed out of 120 → (30 ÷ 120) × 100 = 25% To find a value: Value = (Percent ÷ 100) × Number 15% of 200 → (15 ÷ 100) × 200 = 30 Percentage Increase & Decrease Percentage change measures how much a value has grown or shrunk relative to its original: ((New − Old) ÷ Old) × 100 Increase: $50 → $65 → ((65−50)÷50)×100 = +30% Decrease: $80 → $60 → ((60−80)÷80)×100 = −25% A positive result = increase; a negative result = decrease Discount & Sale Price To find the sale price after a discount: Sale Price = Original × (1 − Discount% ÷ 100) $120 jacket at 30% off → $120 × 0.70 = $84 Savings = Original − Sale Price → $120 − $84 = $36 saved Reverse (find original): Original = Sale ÷ (1 − Discount% ÷ 100) Markup vs Profit Margin Both measure profit, but against different bases — easy to confuse: Markup % — profit as % of cost : (Profit ÷ Cost) × 100 . Cost $40, sell $60 → (20÷40)×100 = 50% markup Margin % — profit as % of selling price : (Profit ÷ Selling Price) × 100 . Same product → (20÷60)×100 = 33.3% margin Markup is always higher than margin for the same product Pro Tips for Percentage Calculations Reverse percentage trick: 16% of 25 = 25% of 16 = 4. Flip the numbers when one is easier to work with mentally. Never confuse markup and margin — a 50% markup is only a 33.3% margin. Use the Markup mode to see both side by side. Percentage points ≠ percent change — if a rate rises from 4% to 6%, that's 2 percentage points but a 50% increase. Tip splitting: enter the number of people in the Tip mode to get the exact per-person amount including tip.

Frequently Asked Questions Common questions about calculating percentages, discounts, tips, and more. Still stuck? Contact us . How do I calculate what percent one number is of another? Formula: (Part ÷ Whole) × 100 Example: 25 is what % of 200? → (25 ÷ 200) × 100 = 12.5% Use the Basic tab's "X is what % of Y?" calculator for instant results How do I calculate percentage increase or decrease? Increase: $50 → $65 → ((65−50)÷50)×100 = +30% Decrease: $80 → $60 → ((60−80)÷80)×100 = −25% Use the Change tab and enter both values for an instant result How do I calculate a discount price? Formula: Sale Price = Original × (1 − Discount% ÷ 100) Example: $80 with 25% off → $80 × 0.75 = $60 Savings = $80 − $60 = $20 Use the Discount tab for instant results including your savings amount How do I calculate a tip? Formula: Tip = Bill × Tip% ÷ 100 Example: $45 bill at 18% → $45 × 0.18 = $8.10 tip , $53.10 total The Tip tab also splits the total across multiple people automatically What is the difference between markup and margin? Markup % = (Profit ÷ Cost) × 100 — profit relative to cost Margin % = (Profit ÷ Selling Price) × 100 — profit relative to revenue Example: cost $40, sell $60 → Markup = 50% , Margin = 33.3% Markup is always higher than margin for the same product How do I find the original price before a discount? Formula: Original = Sale Price ÷ (1 − Discount% ÷ 100) Example: $60 after 25% off → $60 ÷ 0.75 = $80 original The Discount tab handles reverse calculations automatically How do I calculate 20% of a number quickly? 20% of 350 → 350 × 0.20 = 70 Or: 350 ÷ 5 = 70 — same answer, easier mentally Use the Basic tab's "What is X% of Y?" for any percentage instantly Can I use this percentage calculator on my phone? Works on desktop, tablet, and mobile browsers No app download or account sign-up required 100% free with no ads blocking your results Tested on Chrome, Firefox, Safari, and Edge Have a question not answered here? Related Calculator Tools Explore more free online calculators and converters. Scientific Calculator Trigonometry, logarithms, powers, roots, and memory functions. Scientific Calculator Trigonometry, logarithms, powers, roots, and memory functions. Loan EMI & Mortgage Calculator Calculate monthly EMI, total interest, and repayment schedule. Loan EMI & Mortgage Calculator Calculate monthly EMI, total interest, and repayment schedule. Compound Interest Calculator Calculate growth with compound interest across any period and frequency. Compound Interest Calculator Calculate growth with compound interest across any period and frequency. BMI Calculator Calculate your Body Mass Index using height and weight. Calculate your Body Mass Index using height and weight. Age Calculator Find exact age in years, months, and days from any date. Find exact age in years, months, and days from any date. Unit Converter Convert length, weight, temperature, volume and more. Convert length, weight, temperature, volume and more. Fraction Calculator Add, subtract, multiply, and divide fractions with ease. Fraction Calculator Add, subtract, multiply, and divide fractions with ease. Currency Converter Live exchange rates for 150+ world currencies. Currency Converter Live exchange rates for 150+ world currencies. This tool will be released soon. Stay tuned!