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Calculators

56 calculators for every project

Materials, sizes, clearances, energy costs and budgets. Each one shows its method and sources, saves to My Home, and makes a shareable link with your numbers.

Walls & floors

Room area calculatorSquare footage, perimeter and wall area for a room, with an optional bump-out or closet.Paint calculatorHow many gallons of paint and primer a room needs.Light reflectance value (LRV) estimatorEstimate how light or dark a paint color reads from its hex code.Wallpaper roll calculatorRolls of wallpaper needed, accounting for pattern repeat.Flooring calculatorSquare feet, boxes and underlayment for any flooring.Tile calculatorTiles, boxes and thinset for a floor, wall or backsplash.Grout calculatorPounds of grout from tile size, thickness and joint width.

Kitchen

Countertop square footageCountertop and backsplash area, slab count and cost.Kitchen work triangle checkerCheck sink, range and fridge spacing against NKBA guidelines.Appliance energy cost comparisonCompare two models by yearly and lifetime electricity cost.

Bath & water

Water-saving fixture calculatorGallons and dollars saved by low-flow toilets and showerheads.Bathroom clearance checkerCheck toilet and vanity spacing against code minimums and NKBA recommendations.Water heater size (first-hour rating)Size a tank water heater by your busiest hour of hot water use.Tankless water heater sizingFlow rate and heating power a tankless heater needs.

Systems

Lighting lumens calculatorHow many lumens and bulbs a room needs.Chandelier and pendant sizeFixture diameter, height and hanging height for your room.EV home charging calculatorCharging time, monthly cost and circuit size for Level 2 charging.Circuit load checkerWill these devices overload one circuit?Room AC / heat pump BTU calculatorCooling capacity for one room, using the ENERGY STAR sizing chart.Heat pump vs gas furnace costCompare yearly heating cost of a gas furnace and a heat pump.Recommended insulation R-valueTarget R-values by DOE climate zone, from the ENERGY STAR table.Insulation depth and volumeHow many inches of insulation to add to reach a target R-value.

Windows, doors & energy

Solar system size and costSystem size, panel count and gross cost from your yearly electricity use.Security camera storageStorage needed for continuous or motion recording.Standby power (phantom load) costWhat always-on electronics cost you per year.Replacement window measuring helperTurn your six measurements into an order size and a squareness check.Door rough opening calculatorRough opening for a prehung door.

Furnishings

Sofa and coffee table fitCheck a sofa against your wall and plan the coffee table.TV size and viewing distanceIdeal seating distance and mount height for a TV.Bed size fit checkerWill this bed fit with comfortable walkways?Rug size calculatorThe right rug size for a living room, dining room or bedroom.Curtain size calculatorRod length, panel count and panel length.

Decor & storage

Picture hanging heightExactly where to put the nail.Mirror over a console or vanityMirror width and placement over furniture.Closet rod and shelf plannerHanging space and standard heights for a reach-in closet.Shelf and board calculatorShelf count and boards to buy for a wall of shelves.Desk, chair and monitor heightErgonomic heights based on your height.Stove or fireplace heat outputRough heat output needed to warm a space.

Exterior

Roofing calculatorRoof squares, shingle bundles and underlayment from your footprint and pitch.Siding calculatorSquares of siding for walls and gables.Exterior paint calculatorGallons to paint your house exterior.Gutter size and downspoutsPick 5 in or 6 in gutters and count downspouts.Garage floor epoxy calculatorKits or gallons for an epoxy garage floor.

Outdoor living

Deck boards, joists and screwsMaterials for a simple rectangular deck.Concrete calculatorCubic yards or bags for a slab or pad.Paver patio calculatorPavers, base gravel and bedding sand.Fence materials calculatorPosts, rails, pickets and concrete for a wood fence.Mulch, soil and gravel calculatorCubic yards and bags for beds and paths.Plant spacing calculatorHow many plants fill a bed at a given spacing.Low-voltage landscape lightingTransformer size for path and accent lights.

Whole-home projects

Drywall calculatorSheets and screws for walls and ceilings.Baseboard and trim calculatorLinear feet and pieces of baseboard, crown and door casing.Basement wall framing and foamStuds, plates and rigid foam for finishing basement walls.Wheelchair ramp lengthRamp run length and landings from total rise.

Budget and money

Project budget and contingencyAdd contingency and see what to save each month.Home improvement loan paymentMonthly payment and total interest for a loan or HELOC draw.