Is this percentage calculator free?

Yes, completely free with unlimited calculations. No registration required. Your calculation history is stored locally in your browser for privacy.

Percentage Calculator

Calculate percentages instantly with three modes: find a percentage of a number, determine what percent one number is of another, or calculate the percentage change between two values. Free, real-time, and works on any device.

Real-time

Enter Values

Percentage

Of Number

Value (Part)

Total (Whole)

From (Original Value)

To (New Value)

Result

Enter values to calculate

Calculation History

No history yet. Calculate a percentage and save it to start tracking.

The Percentage Calculator You Actually Need

Percentages come up everywhere — shopping discounts, exam scores, financial growth, recipe adjustments, and data analysis. Our Percentage Calculator handles the three most common percentage problems: finding a percentage of a number, determining what percent one value is of another, and calculating the percentage change between two values. Everything updates in real-time as you type, with clear formula breakdowns so you can learn while you calculate.

How to Use the Percentage Calculator

Choose Your Mode

Select a tab: X% of Y to find a value, Find % to determine the percentage, or % Change to calculate increase or decrease between two numbers.

Enter Your Numbers

Type your values into the input fields. Results update instantly as you type — no need to press a calculate button.

Read the Result & Breakdown

View the result, the formula used, and a visual bar. Save calculations to your history for reference or export them as CSV.

Percentage Formulas Explained

Calculation	Formula	Example
X% of Y	Y × (X / 100)	25% of 200 = 200 × 0.25 = 50
X is what % of Y	(X / Y) × 100	50 is (50/200) × 100 = 25% of 200
% Change	((New − Old) / Old) × 100	80 → 100 = +25% increase
% Increase	Value × (1 + X/100)	200 + 25% = 200 × 1.25 = 250
% Decrease	Value × (1 − X/100)	200 − 25% = 200 × 0.75 = 150

Percentage Tips

The Flip Trick

X% of Y always equals Y% of X. So 8% of 50 = 50% of 8 = 4. When one calculation seems hard, flip it for an easier one.

Quick 10% Method

To find 10%, move the decimal one place left. 10% of 350 = 35. Then: 20% = 70, 5% = 17.5, 15% = 52.5.

% Change Direction Matters

A 50% increase then 50% decrease does NOT return to the original. $100 +50% = $150, then −50% = $75. The base changes after each step.

Percentages vs. Percentage Points

Going from 10% to 15% is a 5 percentage point increase but a 50% relative increase. Context determines which to use.

Frequently Asked Questions

How do I find a percentage of a number?

Multiply the number by the percentage divided by 100. For example, 25% of 200 = 200 × (25/100) = 200 × 0.25 = 50. Use the “X% of Y” tab.

How do I calculate what percentage one number is of another?

Divide the part by the whole and multiply by 100. For example, 50 is what % of 200? = (50 ÷ 200) × 100 = 25%. Use the “Find %” tab.

How do I calculate percentage change?

Percentage Change = ((New Value − Old Value) / Old Value) × 100. A positive result means increase, negative means decrease. Example: from 80 to 100 = +25% increase.

Is this calculator free?

Yes, completely free with unlimited calculations. No registration required. Your history is stored locally on your device for privacy.