Arithmetic
Percentage Calculator
Solve every common percentage scenario—find the part, the whole, the percentage itself, or the percent change between two values.
Switch between finding parts, wholes, raw percentages, or percentage change.
Core percentage relationships
part = whole × (percentage ÷ 100)
Depending on the selected mode the calculator rearranges the same relationship to isolate the unknown value. Percent change uses ((new − old) ÷ old) × 100.
How to use
- Choose the mode that matches your question (Part, Whole, Percent, or Change).
- Fill in the known values in the input fields that appear.
- Read the solved value in the results stack immediately below the inputs.
Example
Input: Mode = Part, Whole = 150, Percent = 20
Output: Part = 30
FAQ & notes
Can I enter negative numbers?
Yes. Negative amounts work for change calculations and for scenarios such as refunds or debt reductions.
How is percent change different from percent of?
Percent change compares an old value to a new value and reports the relative difference, while percent of answers “X is what percent of Y.”