Decision calculator library

Start with the decision you actually face. Each tool exposes the assumptions, shows the math, and tells you when reasonable changes can flip the modeled result.

Cars · Repair or replace

Car Repair vs. Replace

Compare repair + keep with replacing now over the same horizon.

Calculator →Guide →Decision center →

Appliances · Repair or replace

Appliance Repair vs. Replace

Compare repair life, replacement life, operating cost, and breakeven.

Calculator →Guide →

Home · HVAC

HVAC Repair vs. Replace

Include a delayed replacement when a repair will not last through the horizon.

Calculator →Guide →

Home · Heating

Heat Pump vs. Gas Furnace

Compare installed cost, delivered heat, operating cost, and performance assumptions.

Calculator →Guide →

Home · Water heating

Water Heater Repair vs. Replace

Compare repair now, standard tank replacement, and heat-pump water heating.

Calculator →Guide →