Percent Error Calculator
Last updated: November 5, 2026
Calculate absolute error, relative error and percent error between measured and accepted values.
Percent error
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- Absolute error: —
- Relative error: —
- Measurement direction: —
On this page
Quick summary: Calculate absolute error, relative error and percent error between measured and accepted values.
Read the complete guide
Updated reference sections in this guide are in English.
What this calculator estimates
Calculate absolute error, relative error and percent error between measured and accepted values.
How to use it
Enter Measured or observed value; Accepted or true value. Select Calculate to update the results.
How the calculation works
Percent error is the absolute difference divided by the absolute accepted value, multiplied by 100.
Worked example: starting scenario
| Measured or observed value | 98 |
|---|---|
| Accepted or true value | 100 |
| Percent error | 2% |
|---|---|
| Absolute error | 2 |
| Relative error | 0.02 |
| Measurement direction | Measured value is lower |
Important limitations
The accepted value cannot be zero. Context may require signed error instead of absolute percent error.
The reference value defines the denominator
With measured value 105 and accepted value 100, absolute error is 5 and percent error is 5%. Reversing the roles gives 5/105 × 100, about 4.76%, so the comparison is not symmetric. Percent error needs a nonzero accepted value. The signed difference tells the direction, while an absolute-percent-error result discards that sign.