Your home, by the numbers.
Free calculators for buying, owning, renovating, and improving your home.
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Comfortable home budget
Popular calculators
Home affordability
Find a home budget that fits your income, monthly expenses, and cash on hand.
Make your next moveMortgage payment
See your real monthly payment, including taxes, insurance, HOA, and PMI.
Make your next moveRenovation cost
Build a renovation budget with editable project scope, finish level, labor, and contingency.
See the bigger picture.Flooring
Measure your rooms, add a waste allowance, and estimate flooring and installation costs.
Measure twice. Plan once.Concrete
Estimate slabs, footings, walls, columns, circular slabs, and post holes in bags or cubic yards.
See the bigger picture.Paint
Estimate paint for your walls and ceilings, with doors and windows taken out.
Measure twice. Plan once.Mortgage payoff
Estimate a payoff month and compare monthly, annual, and one-time extra principal payments.
See the bigger picture.What are you planning?
Buying a Home
Understand your budget, mortgage payment, and cash needed before making an offer.
5 toolsOwning a Home
Understand the cost of ownership and explore a plan for your mortgage.
6 toolsRenovate
Plan a renovation budget and measure the materials before you start.
14 toolsOutdoor Projects
Measure your garden, lawn, patio, fence, and deck projects.
9 toolsEnergy
Explore home comfort, insulation, and the cost of electricity.
4 toolsMoney
Make a plan for savings and explore the tradeoffs of investing.
4 toolsConverters
Everyday measurements, translated in an instant.
6 toolsThe right tool for your next decision.
Home affordability
Find a home budget that fits your income, monthly expenses, and cash on hand.
Mortgage payment
See your real monthly payment, including taxes, insurance, HOA, and PMI.
PMI estimate
Estimate private mortgage insurance and see how down payment affects loan-to-value.
Closing costs
Plan the cash you need for a down payment, closing fees, prepaids, and reserves.
Rent vs buy
Compare home equity with the savings you could invest while renting.
Flooring
Measure your rooms, add a waste allowance, and estimate flooring and installation costs.
Paint
Estimate paint for your walls and ceilings, with doors and windows taken out.
Room area
Find the area of a rectangular room from your measurements.
Square footage
Calculate total square footage across identical spaces, in feet or feet and inches.
Drywall
Estimate wall and ceiling sheets with common sizes and a waste allowance.
Compound interest
See how your starting balance and regular contributions can grow with compounding.
Savings goal
Turn a savings goal into a monthly plan and estimate your future balance.
Investment forecast
Explore possible portfolio growth with contributions and three return scenarios.
Feet & inches
Convert feet and inches to total inches, or split inches into feet and inches.
Feet to Meters
Instantly convert feet to meters, or switch direction.
Square Feet to Acres
Instantly convert square feet to acres, or switch direction.
Square Feet to Square Meters
Instantly convert square feet to square meters, or switch direction.
Gallons to Liters
Instantly convert US gallons to liters, or switch direction.
Fahrenheit to Celsius
Instantly convert °F to °C, or switch direction.
Renovation cost
Build a renovation budget with editable project scope, finish level, labor, and contingency.
Mortgage payoff
Estimate a payoff month and compare monthly, annual, and one-time extra principal payments.
Extra mortgage payments
Compare extra principal amounts and see how much time and interest they can save.
Pay extra or invest?
Compare earlier mortgage payoff with investing the same monthly cash budget.
Concrete
Estimate slabs, footings, walls, columns, circular slabs, and post holes in bags or cubic yards.
Mulch
Estimate mulch volume, purchase quantities, and material costs from your area and depth.
Gravel
Estimate gravel volume, purchase quantities, and material costs from your area and depth.
Topsoil
Estimate topsoil volume, purchase quantities, and material costs from your area and depth.
Roofing
Estimate pitched roof area, roofing squares, bundles, and underlayment.
Stairs
Explore stair risers, treads, run, angle, and stringer geometry.
Fence
Estimate fence posts, panels, pickets, rails, and post-hole concrete.
Tile
Estimate tile counts, boxes, grout spacing, and a waste allowance for floors, walls, and backsplashes.
Deck materials
Estimate decking boards, joists, support posts, fasteners, and concrete.
Sod
Estimate lawn area, sod pieces, waste, and cost across multiple lawn sections.
Pavers
Estimate pavers, base gravel, bedding sand, and material costs for a patio or path.
Wallpaper
Estimate whole wallpaper rolls using wall height, roll size, and pattern-repeat losses.
Siding
Estimate exterior siding area, gables, whole packages, and material costs.
Insulation
Estimate insulation quantities, target thickness, cavity fit, and material cost.
HVAC / BTU
Explore approximate heating and cooling loads with clearly labeled rule-of-thumb assumptions.
Electricity cost
Estimate electricity consumption and monthly running costs from watts, usage, and your local rate.
Appliance energy cost
Estimate electricity consumption and monthly running costs from watts, usage, and your local rate.
Home equity
Estimate your equity, loan-to-value, and net equity after modeled selling costs.
Property tax
Estimate annual and monthly tax using assessed value, exemptions, and a combined local rate.
True monthly home cost
Budget beyond the mortgage with taxes, insurance, HOA, maintenance, and utilities.
Less “probably.”
More “here’s the plan.”
A calculator should help you understand a decision, not just give you a number. We show the assumptions, explain the math, and leave you in control.
How MansionMath worksThe whole picture
Costs, tradeoffs, and useful breakdowns. No mystery totals.
Private by design
Calculations run in your browser. No account or financial data uploads.
Built to explore
Change an assumption and see what happens. The math keeps up.