Statistics & graphs · SL/HL
Error Bar Range Calculator
Enter the central value and the error-bar magnitude.
Your values
Start with the example or enter your own values. Use a dot for decimals and e for scientific notation.
Calculated locally. No account or input upload.
Result & working
ExampleThe calculator is loading. The worked example is also shown below.
Step-by-step working
The formula
lower = mean − error
upper = mean + error
| Symbol | Meaning |
|---|---|
| error | The quantity represented by the bar, such as SD or SE. |
When to use this calculator
This tool formats symmetric bars; it does not decide whether SD, SE or confidence intervals are the right choice.
Worked example
The page opens with these example values. The result below is pre-generated for reference.
- lower = mean − error = 12.4 − 0.8 = 11.6
- upper = mean + error = 12.4 + 0.8 = 13.2
12.4 ± 0.8
Common mistakes
- Never infer statistical significance solely from whether error bars overlap.