Everyday LifeGenerated accuracy model review: 2026-05-06

Gas Mileage (MPG) accuracy and testing

This page documents how Calwarden builds trust for this calculator: source notes, regression-style default tests, limitations, assumptions, unit handling, rounding, and visible change history.

Formula source

1. **Distance** = End Odometer - Start Odometer. 2. **MPG** = Distance / Gallons Used. 3. **Cost per Mile** = (Gallons × Price) / Distance.

Test cases

Default input regression check

Generated from the checked-in default inputs and calculate function.

Inputs

Start Odometer: 10,000 mi
End Odometer: 10,350 mi
Gallons to Refill: 12.5 gal
Price per Gallon: $3.5

Expected outputs

MPG: 28
Cost per Mile: $0.13
Distance Traveled: 350 mi

Known limitations

This page documents the checked-in calculator logic and does not certify results for every real-world edge case.
Use the result as a planning estimate unless the calculator page states a stricter purpose.

Assumptions

The tank is filled to the same level at the start and end of the measurement.
Odometer readings belong to the same trip window.
Gallons used and distance traveled are both positive values.

Unit handling

Start Odometer accepts values in mi.
End Odometer accepts values in mi.
Gallons to Refill accepts values in gal.
Price per Gallon accepts values in $.
Cost per Mile is displayed as currency.
Distance Traveled is displayed in mi.

Rounding rules

Number displays use up to 2 decimal places in the calculator UI.
Currency outputs are displayed with standard US dollar formatting.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current gas-mileage-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for Gas Mileage (MPG).

Calculator transparency

Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.

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