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EV & CarsGenerated accuracy model review: 2026-05-06

Fuel Cost per Mile Calculator 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

  • Cost per mile = fuel price / MPG. Monthly gallons = monthly miles / MPG.

Test cases

Default input regression check

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

Inputs

  • Fuel Price Preset: eia_us_regular_gasoline_2026_05_04
  • Fuel Price: 3.8 $/gal
  • Vehicle MPG Preset: epa_2026_honda_crv_fwd
  • Fuel Economy: 28 MPG
  • Monthly Miles: 1,000 mi

Expected outputs

  • Fuel Cost per Mile: $0.15
  • Monthly Fuel Cost: $148.40
  • Annual Fuel Cost: $1,780.80
  • Monthly Fuel Used: 33.33 gal

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

  • All prices, fees, rates, and vehicle assumptions are user-entered.
  • Calculations run locally in your browser and are not stored by Calwarden.
  • This is planning math, not financial, tax, insurance, legal, or mechanical advice.

Unit handling

  • Fuel Price Preset accepts one of the configured options.
  • Fuel Price accepts values in $/gal.
  • Vehicle MPG Preset accepts one of the configured options.
  • Fuel Economy accepts values in MPG.
  • Monthly Miles accepts values in mi.
  • Fuel Cost per Mile is displayed as currency.
  • Monthly Fuel Cost is displayed as currency.
  • Annual Fuel Cost is displayed as currency.
  • Monthly Fuel Used is displayed in gal.

Rounding rules

  • Number displays use up to 2 decimal places in the calculator UI.
  • Currency outputs are displayed with standard US dollar formatting.
  • Input precision follows configured step values where provided.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current fuel-cost-per-mile-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for Fuel Cost per Mile Calculator.

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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