Percentage Difference Calculator
Compare two nonnegative values relative to their average.
Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
Example Calculation
- First value: 80
- Second value: 100
80 and 100 differ by about 22.2222% relative to their average.
Frequently asked questions
How do I use this calculator?
Enter first value, second value. The result updates automatically. Use Reset to restore the example values.
What method does it use?
Difference (%) = |a − b| / [(a + b) / 2] × 100. Follow the units and definitions shown with the inputs to apply this relationship consistently.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.