Home & Construction Calculators
Whether you are buying your first house, renovating a kitchen, landscaping a yard, or just trying to lower your electricity bill, our 21 home and construction calculators help you plan with confidence. Determine how much house you can afford, compare renting versus buying, or evaluate rental property returns. For renovation projects, calculate the exact amount of paint, tile, concrete, mulch, or gravel you need — no more guessing at the hardware store. Estimate roofing materials, HVAC capacity with the BTU calculator, and monthly electricity costs for any appliance. Homeowners can also model refinancing scenarios, HELOC draws, and down payment strategies. We even cover automotive tools like gas mileage, fuel cost, and tire sizing. All calculators are free and work instantly in your browser.
Home Buying & Finance
Affordability, rent vs. buy, rental property, HELOC, refinance, and down payment.
House Affordability Calculator
Find out how much home you can afford based on income and debts.
Rent vs Buy Calculator
Compare the true cost of renting versus buying over time.
Rental Property Calculator
Estimate cash flow, cap rate, and ROI on rental investments.
HELOC Calculator
Estimate home equity line of credit payments and available equity.
Refinance Calculator
Compare your current mortgage with a new rate to see savings.
Down Payment Calculator
Calculate down payment amount and its effect on monthly payments.
Building & Renovation
Materials calculators for paint, tile, concrete, mulch, gravel, and roofing.
Square Footage Calculator
Calculate area in square feet for rooms, lots, or any shape.
Paint Calculator
Estimate gallons of paint needed for walls, ceilings, or trim.
Tile Calculator
Calculate number of tiles needed including waste percentage.
Concrete Calculator
Estimate cubic yards of concrete for slabs, footings, and columns.
Mulch Calculator
Calculate mulch volume in cubic yards for garden beds.
Gravel Calculator
Estimate gravel quantity in tons or cubic yards for driveways and paths.
Roofing Calculator
Estimate roofing squares and materials for roof replacement.
Energy & Utilities
Electricity costs, HVAC sizing, and weather calculations.
Electricity Calculator
Estimate electricity cost for any appliance by wattage and usage.
BTU Calculator
Size your heating or cooling system based on room dimensions.
Wind Chill Calculator
Find the feels-like temperature based on wind speed and air temp.
Automotive & Other
Fuel costs, gas mileage, horsepower, tire sizing, and networking.
Gas Mileage Calculator
Calculate your vehicle's miles per gallon from fill-up data.
Fuel Cost Calculator
Estimate fuel cost for any trip based on distance and gas price.
Horsepower Calculator
Calculate engine horsepower from torque and RPM.
Tire Size Calculator
Compare tire dimensions and see speedometer difference.
IP Subnet Calculator
Calculate subnet masks, network ranges, and available hosts.
Frequently Asked Questions
How do I calculate how much paint I need?
Measure the total wall area in square feet (height x width for each wall), subtract windows and doors, and divide by the paint coverage rate (typically 350-400 sq ft per gallon). Our paint calculator handles rooms with multiple walls, doors, and windows and tells you exactly how many gallons to buy for the number of coats you want.
How much concrete do I need for a slab or footing?
Measure length, width, and thickness of the area in feet. Multiply all three to get cubic feet, then divide by 27 to convert to cubic yards (the standard ordering unit). Our concrete calculator handles slabs, footings, columns, and steps, and adds a recommended 10% waste factor so you do not run short during the pour.
Should I refinance my mortgage?
A refinance makes sense when the interest savings over the remaining loan term exceed the closing costs. Our refinance calculator compares your current loan with the new terms, showing monthly savings, total interest saved, and the break-even point — the number of months it takes for savings to recoup closing costs.
How is electricity cost calculated?
Electricity cost equals power consumption (watts) x hours of use x your utility rate per kilowatt-hour. Our calculator lets you enter the wattage of any appliance and your local rate to see daily, monthly, and annual costs. This helps identify energy hogs and estimate the savings from switching to more efficient equipment.