By Meraj Uddin Provat · Last reviewed May 23, 2026 · Editorial Standards

CalcCottage

Simple calculators for big money decisions

Find the calculator. Change the numbers. Understand the decision.

CalcCottage keeps home-buying, mortgage, energy, and EV math readable on a phone. No account, no spreadsheet, no guessing what a result means.

Start here

Choose by decision, not by jargon.

Cards are grouped around what people actually ask before buying, borrowing, upgrading, or moving.

$ Home buying Closing Cost Calculator by State Estimate buyer fees, title costs, transfer taxes, and total cash needed. M Mortgage Mortgage Payment Calculator Full monthly PITI plus PMI, total interest and payoff date. = Schedule Amortization Schedule Calculator Month-by-month principal vs interest, plus extra payments. = Auto Auto Loan Calculator Real car payment with sales tax, fees, trade-in, and rolled-in negative equity. = Savings Retirement Calculator Project your nest egg and the yearly income it can pay you. H Affordability Home Affordability Calculator How much house you can afford across three DTI scenarios. = Savings Compound Interest Calculator Future value of a starting amount plus monthly deposits over time. v Payoff Mortgage Payoff with Extra Principal See how extra payments change interest and payoff date. = Savings 50/30/20 Budget Calculator Your real needs/wants/savings split vs the 50/30/20 target. = Savings Net Worth Calculator Everything you own minus everything you owe, with asset mix. = Debt Debt Payoff Calculator Months to zero, total interest, and what an extra payment saves. = Decision Rent vs Buy Calculator Compare rent, mortgage, taxes, appreciation, and your break-even year. R Refinance Refinance Break-Even Calculator Months to recoup refinance closing costs. # Taxes Property Tax Calculator by County Estimate annual taxes with local rates and home value. % Qualify Debt-to-Income (DTI) Calculator Front and back-end DTI vs FHA, VA and conventional limits. = Auto Car Affordability Calculator How much car your income actually supports. = Savings Savings Goal Calculator When you hit a goal and the monthly to get there. = Debt Student Loan Payoff Calculator Real payoff date, interest, and what extra does. = Debt Credit Card Minimum Payment Calculator The real cost of paying only the minimum. = Savings CD & Savings Calculator What a CD or high-yield savings grows to. D Savings Down Payment Savings Calculator How long to save your down payment, with growth. 15 Compare 15-Year vs 30-Year Mortgage Payment vs lifetime-interest trade-off. B Payoff Biweekly Mortgage Calculator Monthly vs biweekly — interest saved, years sooner. V Veterans VA Loan Calculator Funding fee, zero down, no PMI — full payment. % Mortgage FHA vs Conventional Loan Calculator Compare monthly payment, upfront fees, mortgage insurance, and loan cost. P Equity PMI Removal Calculator When PMI drops off — 78%, 80% and appreciation routes. = Savings Emergency Fund Calculator How big your safety net should be and when you reach it. = Savings Roth vs Traditional Calculator Which wins after tax — decided by your tax rates. HE Equity HELOC vs Cash-Out Refinance Compare payments, rates, fees, and total borrowing cost. = Auto Lease vs Buy a Car Calculator True net cost of leasing vs buying over the same period. = Auto Auto Refinance Calculator Real savings from refinancing a car loan, with break-even. = Home Home Sale Net Proceeds Calculator What you actually walk away with after selling. = Mortgage Mortgage Recast Calculator Lump sum, same rate and term, lower payment. # Investing Cap Rate & Cash-on-Cash Calculator Rental returns: cap rate, cash-on-cash, DSCR, verdict. EV Transportation EV vs Gas Total Cost of Ownership Compare fuel, charging, maintenance, incentives, and resale. S Energy Solar Payback Calculator by State Estimate panel cost, incentives, savings, and payback window. H Home energy Heat Pump vs Gas Furnace Lifetime Cost Compare equipment, energy prices, incentives, and replacement timing. + Renovation Home Renovation ROI Calculator Estimate project cost, resale value, and payback percentage. S Energy Solar Panel Sizing Calculator How many panels and kW you need from your bill. + Energy Insulation ROI Calculator Energy savings, 25C credit and climate-zone payback.

Local defaults

State pages should feel useful, not duplicated.

Use state and county pages for different transfer taxes, property-tax habits, utility prices, and incentive assumptions.

01

Fast first result

Default numbers let visitors understand the calculator before editing every field.

02

Plain assumptions

Each calculator explains what is included, what is excluded, and what can change locally.

03

Mobile friendly

Large targets, one-column forms, readable labels, and no hidden interactions.

New guide

First-Time Home Buyer Guide — The Honest Step-by-Step

Seven steps in the order they actually matter, each with the calculator that gives you a real answer.