Examples
Examples
Try the starting example
- Measured rollout distance (m)
- 10
- Wheel revolutions over that distance
- 5
- Current computer circumference setting (mm)
- 2100
- Trip distance displayed using old setting (km)
- 100
- Measured circumference (mm)
- 2000
- Measured/current setting ratio
- 0.952381
- Corrected trip distance under rollout (km)
- 95.238095
- Circumference setting change (%)
- -4.761905
Try another scenario
- Measured rollout distance (m)
- 10
- Wheel revolutions over that distance
- 4
- Current computer circumference setting (mm)
- 2100
- Trip distance displayed using old setting (km)
- 100
- Measured circumference (mm)
- 2500
- Measured/current setting ratio
- 1.190476
- Corrected trip distance under rollout (km)
- 119.047619
- Circumference setting change (%)
- 19.047619
Calculation method
Calculation method
Measured circumference (mm)
1000×measured metres/revolution count.
Measured/current setting ratio
Measured circumference/current setting.
Corrected trip distance under rollout (km)
Displayed old-setting trip×measured/current ratio.
Circumference setting change (%)
100×(measured/current−1).
Symbols and units
- a
- Measured rollout distance (m)
- b
- Wheel revolutions over that distance
- c
- Current computer circumference setting (mm)
- d
- Trip distance displayed using old setting (km)
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 measured rollout calibration using the same wheel loading and tyre setup as the measurement. It does not infer nominal tyre circumference or correct GPS distance.
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: arithmetic model background ↗
Background reading; this does not imply endorsement or independent review of SumFizz.