Methodology

Every calculator is backed by a versioned methodology — the formula, default assumptions, unit and confidence rules, data requirements, and validation benchmark. Methodology changes are versioned and never overwrite your historical estimates.

Appliance operating cost

Energy use × your state’s average rate, with a usage and rate range.

Electricity bill

Monthly kWh × state-average rate; the range widens when usage is estimated.

Home maintenance rules

Climate, component, pet, and pool-gated tasks with trigger-based intervals.

Home reserve forecast

A seeded, reproducible simulation over component lifespan and replacement cost.