Math calculators

Percentage calculator

Find X% of Y, what percent one number is of another, percentage change, increase or decrease by a percent, and percentage points.

Inputs

Percent%Value

Results

Methodology

Conventions

Percentages are entered in percent: 15 means 15%.
Percentage change is measured against the starting value; a change in a rate that is itself a percentage is also given in percentage points.

References

Any school algebra text

Formulas

Percent of: \frac{p}{100} \cdot v
What percent: 100 \cdot \frac{\text{part}}{\text{whole}}
Percentage change: 100 \cdot \frac{\text{to} - \text{from}}{|\text{from}|}
Increase or decrease: v \cdot (1 \pm p/100)