Percentage Calculator – Free Online Percent Calculator
Percentage calculations are everywhere: tax calculations, price discounts, tips, and financial growth reports. A small error can mess up a budget or report. This tool does the math for you instantly.
Solve all percentage calculations instantly with three flexible calculation modes. Find percentage changes, percentage increases/decreases, and what percent a number is of another. Access clean formulas and math examples.
How to Use the percentage
By inputting variables into any of the calculation boxes, the page runs JavaScript formulas to solve for percentages, values, or base numbers.
- 1Identify the calculation type you need (What is X% of Y, What is the percent change, or X is what % of Y).
- 2Input your values in the corresponding fields of that calculator module.
- 3Review the answer rendered instantly below the inputs, along with a step-by-step math explanation.
Standard Percentage Formulas
Percentages solve for the ratio of a part to a whole multiplied by 100.
Standard: Value = (Percent ÷ 100) × Whole
Percent Change: % Change = ((New Value − Old Value) ÷ Old Value) × 100Common Reference Values & Comparisons
Refer to this table to study common calculations, reference ratios, or performance profiles for this tool:
| Calculation Scenario | Mathematical Equation |
|---|---|
| Find 20% of 150 | 0.20 * 150 = 30 |
| Find % Change (100 to 120) | ((120 - 100)/100) * 100 = 20% |
| Find base (50 is 10% of what?) | 50 / 0.10 = 500 |
| Find percentage (15 is what % of 60?) | (15 / 60) * 100 = 25% |
| Calculate GST/VAT tax | Price * (Tax Rate / 100) |
Frequently Asked Questions (FAQ)
To find X% of Y, divide the percentage X by 100, then multiply the result by Y. For example, 10% of 50 = (10/100) * 50 = 5.
Percentage change measures the rate of growth or decay between two values. Subtract the old value from the new value, divide by the old value, and multiply by 100.
Yes, it is highly accurate for calculating interest rates, tax values, ROI, discounts, and margins.
Yes, you can enter fractional percentage rates like 7.25% to compute precise interest or tax values.
It normalizes comparisons, making it easy to analyze ratios, changes, and proportions across different scales.
Mastering percentages helps you make informed financial and technical choices. Save this calculator to bypass manual arithmetic and get immediate answers.