All calculators

Every CalcCottage calculator, in one place.

Free, sourced, calibrated to your state. Built for the way real people make real home and energy decisions — not the way a banking widget wants you to.

Home buying 4 calculators

The math behind the biggest purchase most Americans will ever make. State-aware where it matters.

By state

Closing Cost Calculator

Estimate buyer fees, transfer taxes, title insurance, and total cash needed at closing. Covers all 50 US states + DC for Conventional, FHA, VA, USDA, and Cash.

Open → Break-even analysis

Rent vs Buy Calculator

Year-by-year cost comparison including appreciation, opportunity cost on your down payment, and tax savings. Tells you the exact break-even year for your situation.

Open → Loan compare

FHA vs Conventional Loan

Side-by-side: monthly payment, mortgage insurance (PMI vs MIP), total interest, and lifetime cost. Credit-tier rate adjustments built in.

Open → Pay off early

Mortgage Payoff Calculator

See how many years and how much interest you’d save by adding extra to your monthly payment. Optional lump-sum prepayments and balance chart.

Open →

Home energy & EV 3 calculators

2026 federal credits, state rebates, and real climate-zone data — for the decisions where electrification has real money on the table.

By state

Solar Payback Calculator

Estimate system size from your bill, then apply the 30% federal ITC and state credits to find your break-even year. 51-state coverage.

Open → 5-year TCO

EV vs Gas Total Cost of Ownership

Compare 3, 5, 7, or 10-year cost including the $7,500 federal EV credit, state rebates, fuel, maintenance, insurance, and depreciation.

Open → 15-year TCO

Heat Pump vs Gas Furnace

State-calibrated heat pump COP versus your current heating system. Includes the federal 25C credit (30%, $2K cap), state rebates, and panel upgrade.

Open →

Equity & refinance 1 calculator

When and how to pull cash from your home equity.

Side-by-side

HELOC vs Cash-Out Refinance

Compare both options over your time horizon. Your current low mortgage rate vs. fresh refi rate is usually the deciding factor.

Open →

Renovation & value 1 calculator

Which projects pay back at resale, and which are for personal enjoyment.

Cost vs Value

Home Renovation ROI Calculator

Estimate resale value increase for 30+ common projects using Remodeling Magazine 2024 Cost vs. Value data.

Open →

Affordability & taxes 2 calculators

What you can afford and what you’ll owe.

DTI-based

Home Affordability Calculator

Three scenarios (conservative, comfortable, stretch) using your income, debts, and 2026 mortgage rates with full PITI math.

Open → By state

Property Tax Calculator

Annual property tax estimate using state-average effective rates (Tax Foundation 2024) with homestead exemption support.

Open →

Coming soon In development

Refinance Break-Even Calculator Standalone tool. Read the guide while we build it.

Insulation ROI Calculator Attic, wall, basement insulation payback by climate zone.

15-yr vs 30-yr Mortgage Total cost comparison between loan terms.

Cap Rate / Investment Property Cash-on-cash return for rental properties.