Examples
Examples
Try the starting example
- Same-part observations: date, odometer km, thickness mm
- 2026-10-01,0,10 2026-10-10,1000,9 2026-10-20,2000,8
- Externally supplied comparison thickness (mm)
- 3
- Latest observed thickness (mm)
- 8
- Latest thickness minus supplied comparison (mm)
- 5
- OLS observed thickness change per 1000 logged km
- -1
- Observed odometer span (km)
- 2000
- Dates whose thickness increased from prior reading
- None
Try another scenario
- Same-part observations: date, odometer km, thickness mm
- 2026-10-01,0,10 2026-10-10,1000,9 2026-10-20,2000,9
- Externally supplied comparison thickness (mm)
- 3
- Latest observed thickness (mm)
- 9
- Latest thickness minus supplied comparison (mm)
- 6
- OLS observed thickness change per 1000 logged km
- -0.5
- Observed odometer span (km)
- 2000
- Dates whose thickness increased from prior reading
- None
Calculation method
Calculation method
Latest observed thickness (mm)
Last record in required ascending-date log.
Latest thickness minus supplied comparison (mm)
Signed latest measurement−supplied comparison value.
OLS observed thickness change per 1000 logged km
Centered least-squares thickness-versus-odometer slope×1000; undefined when distance does not vary.
Observed odometer span (km)
Last−first logged odometer.
Dates whose thickness increased from prior reading
Expose increases as observations; do not silently interpret replacement or measurement error.
Symbols and units
- a
- Same-part observations: date, odometer km, thickness mm
- b
- Externally supplied comparison thickness (mm)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions & limits
Assumptions & limits
- A descriptive same-part wear-measurement log with no extrapolated replacement date or service guarantee. Conditions, measurement error and actual brake suitability are not inferred from a fitted trend.
Are these inputs private?
These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.
Further reading
OpenStax: ratios, unit rates and supplied measurement arithmetic ↗
Background reading; this does not imply endorsement or independent review of SumFizz.