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Business & eCommerceGenerated accuracy model review: 2026-05-06

GDP 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

  • **GDP = C + I + G + (X - M)** * **C**: Consumption (Household spending on goods/services) * **I**: Investment (Business capital, new housing) * **G**: Government Spending (Infrastructure, defense, salaries) * **(X - M)**: Net Exports (Exports minus Imports)

Test cases

Default input regression check

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

Inputs

  • Consumption (C): 1,000 $B
  • Investment (I): 500 $B
  • Govt Spending (G): 400 $B
  • Exports (X): 200 $B
  • Imports (M): 300 $B

Expected outputs

  • GDP: $1,800.00
  • Net Exports: -$100.00

Known limitations

  • Calculates Nominal GDP (current prices), not Real GDP (constant prices). Does not include the underground economy or unpaid work.

Assumptions

  • This tool uses the expenditure approach only and reports nominal GDP at the input price level.
  • Inputs should be measured over the same period and in the same currency units.
  • The calculator is intended for educational or analytical use, not official national accounts reporting.

Unit handling

  • Consumption (C) accepts values in $B.
  • Investment (I) accepts values in $B.
  • Govt Spending (G) accepts values in $B.
  • Exports (X) accepts values in $B.
  • Imports (M) accepts values in $B.
  • GDP is displayed as currency.
  • Net Exports is displayed as currency.

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 gdp-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for GDP 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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