Experimental data & uncertainty · SL/HL
Rate of change
Find a signed average change per unit time.
Your values
Number formats & units
Use decimal dots in datasets. Single values also accept decimal commas and scientific notation such as 1.2e-3 or 1.2 × 10⁻³.
Calculated locally. No account or input upload.
Result & working
ExampleThe calculator is loading. The worked example is also shown below.
Download results
Excel and CSV files can be imported into Google Sheets.
More results
Show calculation steps
Interpretation & assumptions
Copy & export
Formula & example
The relationship
What the variables mean
| Symbol | Meaning |
|---|---|
| Signed average change per unit time. |
Worked example
- Initial value
- 2.4
- Final value
- 7.8
- Elapsed time
- 12
- Value unit
- mg
- Time unit
- min
0.45 mg/min
Follow the example steps
- Δy = 7.8 − (2.4) = 5.4 mg
- rate = Δy/Δt = 5.4/12 = 0.45 mg/min
Common mistakes
Keep the sign when direction matters.
Incorrect approach
10 → 6, Δt = 2 s: Δx/Δt = +2 s⁻¹
Correct approach
Δx/Δt = (6 − 10)/2 = −2 s⁻¹
More checks before you submit
- Keep the sign if direction of change matters.
Method notes
For a graph, this is the gradient of the secant between two points; instantaneous rate may differ.