How to Use Percentage Calculator: Complete Guide (2026)

What is Percentage Calculator?

Percentage Calculator is a free, browser-based utility on ToolsMinify. Solve the three most common percentage problems in one place: find the percentage of a number (what is 15% of 200?), work out percent change between two values (increase or decrease), and find what percent one number is of another (X is what % of Y?). Enter your numbers and the answer appears instantly - useful for tips, discounts, taxes, grades, and quick everyday math. Everything runs in your browser. It requires no signup, processes data locally when possible, and is built for speed on mobile and desktop.

Free online percentage calculator: find the percentage of a number, calculate percent change (increase or decrease), and work out what percent X is of Y - with the formula and instant results.

Why use Percentage Calculator?

• Free with no account required
• Works on phone, tablet, and desktop
• Fast results with a clean interface
• Pairs with related tools on the same platform

How to use Percentage Calculator - step by step

1. Step 1: Choose the calculation mode: '% of a number', '% change', or 'X is what % of Y'.
2. Step 2: Enter your values in the two fields.
3. Step 3: Read the computed result instantly - no button to press.
4. Step 4: Switch modes to solve a different type of percentage problem.

The Percentage Calculator lives under Calculator Tools. Open the tool page, enter your input in the main field, and results update instantly. Use the copy button to paste output into documents, code editors, or spreadsheets.

Common use cases

Percentage of a number

15% of 200 = 30.

Percentage increase

From 80 to 100 is a 25% increase.

What percent is X of Y

30 is 15% of 200.

Tip calculation

20% of a $45 bill is a $9 tip.

Examples

• Percentage of a number: 15% of 200 = 30.
• Percentage increase: From 80 to 100 is a 25% increase.
• What percent is X of Y: 30 is 15% of 200.
• Tip calculation: 20% of a $45 bill is a $9 tip.

Pro tips

• Bookmark the tool for repeat tasks
• Read the FAQ on the tool page for edge cases
• Try related tools linked at the bottom of each page

Frequently asked questions

How do I calculate a percentage?

To find a percentage of a number, multiply the number by the percentage divided by 100. Formula: result = (percentage / 100) x number. For example, 25% of 80 = (25 / 100) x 80 = 20. Use the '% of a number' mode above to do it instantly.

How do I use the percentage calculator?

Pick the mode that matches your question, type the two numbers, and read the answer. Use '% of a number' for things like tips and taxes, '% change' to compare an old and new value, and 'X is what % of Y' to turn a fraction into a percentage.

What is the difference between percent of a number and percent change?

"Percent of a number" finds a portion - e.g. 15% of 200 = 30. "Percent change" calculates how much something increased or decreased between two values - e.g. from 80 to 100 is a 25% increase. "X is % of Y" finds what percentage one number is of another - e.g. 30 is 15% of 200.

How do I calculate a percentage increase?

Use the "% change" tab. Enter the original value as the starting number and the new value. The tool calculates: ((New − Old) ÷ Old) × 100. A positive result means increase; negative means decrease.

How do I work out a tip percentage?

Use the "% of number" tab. Enter the bill amount and the tip percentage (e.g. 15 or 20). The result is the tip amount. Add it to the original bill for the total.

What is the formula for percentage of a number?

Result = (Percentage ÷ 100) × Number. For example, 25% of 80 = (25 ÷ 100) × 80 = 20.

Is this calculator accurate for VAT and sales tax?

Yes for simple tax calculations. Enter 100 (original price) and your VAT rate (e.g. 20) in the "% of number" tab to find the tax amount (20). Add to the original for the total (120). For reverse VAT (finding pre-tax price), use the "X is % of Y" tab.

Related tools you might need

Explore other calculator tools on ToolsMinify. Related utilities are linked on the Percentage Calculator page to help you complete your workflow without leaving the site.