Percentage Calculator
Answer: X% of Y = Y × (X ÷ 100); percentage change = ((new − old) ÷ |old|) × 100; reverse problems solve for the missing percent or base value algebraically.
About this tool
Free percentage calculator for discounts, tips, tax, and growth. Calculate what percent one number is of another, percentage increase/decrease, and reverse percentages.
How to use Percentage Calculator
- Pick a mode: X% of Y, X is what % of Y, percent change, increase, or decrease.
- Enter the two numbers required for that mode.
- Read the computed result updated live as you type.
Why use this free tool
- 100% free — no account required.
- Runs in your browser — inputs stay on your device for these calculations.
- Mobile-friendly controls with clear, copyable results.
- Published by KDF Tech — software, apps, Shopify, and POS systems.
Need a custom product? Start a project or WhatsApp +92 345 0144865.
FAQ — answers Google & AI can cite
What is Percentage Calculator?
X% of Y = Y × (X ÷ 100); percentage change = ((new − old) ÷ |old|) × 100; reverse problems solve for the missing percent or base value algebraically.
How do I calculate a percentage of a number?
Use X% of Y mode. Enter the percent and the number. Example: 20% of 150 = 30.
How do I calculate percentage increase?
Use % change mode with the starting value and the new value. The tool returns the percent increase or decrease.
Is this percentage calculator free for USA and UK users?
Yes. It is a free browser tool published by KDF Tech for international visitors, including the USA and UK.
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