Free Online Tool

Percentage Calculator

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.

5 calculator modes Instant results Mobile friendly 100% free
0.00
Enter values and click Calculate
Basic Percentage
of
Example: 20% of 200 = 40
is % of
Example: 25 is 12.5% of 200
is
% of
Example: 40 is 20% of 200
Percentage Change
→
Example: $50 → $65 = +30% increase
Example: 100 increased by 15% = 115
Discount Calculator
Example: $120 at 30% off = $84 ($36 saved)
Quick presets:
Tip Calculator
Example: $85 bill with 18% tip = $100.30 total
Quick tips:
Markup & Margin
Example: $40 cost with 50% markup = $60 selling price
Example: $60 selling price with 33.3% margin = $40 cost
No calculations yet
Click any history entry to reuse the result.
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How to Calculate Percentage Online

1

Choose a Calculator Mode

Select the tab that matches your task — Basic, Change, Discount, Tip, or Markup.

2

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.

3

Click Calculate

Press Calculate or the → arrow next to any input row. Results appear instantly — no page reload required.

4

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.

All-in-One Tool — 5 Powerful Percentage Calculators in One

🔢

Basic Percentage

Solve all three core problems: X% of Y, X is what % of Y, and X is Y% of what.

📈

Percentage Change

Calculate percentage increase or decrease between two values.

🏷️

Discount Calculator

Find the sale price and savings amount. Quick-preset buttons for 5%, 10%, 20%, 25%, and 50% off.

💵

Tip Calculator

Calculate tip amount and total bill. Split the total across multiple people for easy group dining.

📊

Markup & Margin

Calculate selling price, profit amount, and profit margin % from cost and markup.

📱

Mobile & Fast

Fully responsive on all screen sizes. Results calculate instantly with no page reload.

How to Calculate Percentages — Formulas & Examples

Basic Percentage Formula

The core formula is: Percentage = (Part ÷ Whole) × 100

30 students passed out of 120 → (30 ÷ 120) × 100 = 25%
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 = $120 − $84 = $36 saved

Markup vs Profit Margin

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

💡 Pro Tips for Percentage Calculations

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Common Conversions

10%= 1/10
20%= 1/5
25%= 1/4
33.3%= 1/3
50%= 1/2
75%= 3/4

Frequently Asked Questions

Divide the part by the whole, then multiply by 100. 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.

Subtract the old value from the new value, divide by the old value, then multiply by 100. Formula: ((New − Old) ÷ Old) × 100. Use the Change tab for instant results.

Multiply the original price by (1 − discount% ÷ 100). Example: $120 at 30% off = $120 × 0.70 = $84. Use the Discount tab with quick-preset buttons for common percentages.

Multiply the bill amount by the tip percentage (as a decimal). Example: $85 bill with 18% tip = $85 × 0.18 = $15.30 tip, total $100.30. Use the Tip tab and adjust the number of people for splitting.

Markup is profit as a percentage of cost. Margin is profit as a percentage of selling price. For a product costing $40 and selling for $60: markup = (20÷40)×100 = 50%, margin = (20÷60)×100 = 33.3%.

Divide the sale price by (1 − discount% ÷ 100). Example: If you paid $70 after a 30% discount, original = 70 ÷ 0.70 = $100.

Divide the number by 10 (10%) then multiply by 2. Example: 20% of 200 = 200 ÷ 10 × 2 = 40. Use the Basic tab for any percentage.

Yes! The calculator is fully responsive and works on all devices — desktop, tablet, and mobile phones.

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Privacy & security notice

This percentage calculator runs entirely in your web browser. No calculations are ever transmitted, stored, or logged by our servers. All data stays on your device.