Know exactly how much to buy.
47 free calculators for paint, concrete, flooring, roofing, insulation, heating, lawns and more. Every result works in feet or meters and shows the formula behind it.
Measure and planArea and volume basics every project starts from.2Heating, cooling and energySize heaters and air conditioners, and work out what appliances cost to run.7Paint, walls and floorsPaint, drywall, tile, flooring and the finishing materials that go with them.12Concrete and masonrySlabs, blocks, bricks, pavers and post footings.7Lumber, framing and roofingBoards, stairs, studs, sheathing, siding and roofs.8Yard, garden and exteriorLawns, beds, gravel, fences, decks, pools and driveways.11
Ready for winter
Size a heater, price a cold night of electric heat, and stock up on firewood before the first freeze.
Measure and plan
Area and volume basics every project starts from.
Heating, cooling and energy
Size heaters and air conditioners, and work out what appliances cost to run.
BTU CalculatorHeating BTU/hr and kW for a room from its size, ceiling height, insulation and climate.AC BTU CalculatorAir conditioner or heat pump size for a room, in BTU, tons and kW.Firewood CalculatorCords, face cords and steres in a stack of firewood, plus its value.Space Heater Cost CalculatorWhat a space heater costs to run per hour, day and month at your electricity rate.Insulation CalculatorThickness and bags or batts of insulation to reach a target R-value.Generator Wattage CalculatorRunning and starting watts for the appliances you need during an outage.Electricity Cost CalculatorDaily, monthly and yearly kWh and cost of running any appliance.
Paint, walls and floors
Paint, drywall, tile, flooring and the finishing materials that go with them.
Paint CalculatorGallons or liters for walls and ceilings, with doors and windows removed.Tile CalculatorNumber of tiles and boxes for floors and walls, with waste for your layout pattern.Flooring CalculatorSquare footage and boxes for laminate, vinyl plank and hardwood, plus trim length.Drywall CalculatorSheets of drywall or plasterboard for walls and ceilings, plus screws.Wallpaper CalculatorRolls of wallpaper by room size, roll type and pattern repeat.Grout CalculatorPounds or kilograms of grout and bags from tile size, thickness and joint width.Thinset CalculatorBags of thinset mortar by area and trowel notch size, with back-buttering.Carpet CalculatorSquare yards, square feet and roll length of carpet for a room.Epoxy Floor CalculatorGallons or liters of garage floor epoxy and kits for any number of coats.Exterior Paint CalculatorGallons or liters of paint for house siding, gables and coats.Deck Stain CalculatorGallons of deck stain for the floor, railings and stairs.Joint Compound CalculatorGallons of drywall mud and feet of tape from area or number of sheets.
Concrete and masonry
Slabs, blocks, bricks, pavers and post footings.
Concrete CalculatorCubic yards, cubic meters and bag counts for slabs, patios and pads.Concrete Block CalculatorCMU blocks for a wall, course by course, plus premixed mortar bags.Brick CalculatorBricks and mortar for a wall, with openings, joint size and waste.Paver CalculatorPavers for a patio or path, plus gravel base and bedding sand.Retaining Wall CalculatorRetaining wall blocks, caps and drainage gravel for a block wall.Rebar CalculatorRebar grid for a slab: bars each way, laps, total length and weight.Post Hole Concrete CalculatorConcrete and bags for fence or deck post holes, less the post.
Lumber, framing and roofing
Boards, stairs, studs, sheathing, siding and roofs.
Roofing CalculatorRoof area, squares and shingle bundles from the house footprint and pitch.Board Foot CalculatorBoard feet, cost and cubic volume for any number of boards.Stair CalculatorRisers, treads, riser height, total run, stringer length and stair angle.Plywood CalculatorSheets of plywood or OSB for subfloors, wall sheathing and roof decks.Baseboard and Trim CalculatorLinear feet or meters and number of pieces of baseboard or crown molding.Rafter Length CalculatorCommon rafter length, overhang, plumb cut angle and number of rafters.Siding CalculatorSquares and square feet or m² of siding for walls and gables.Stud CalculatorWall studs at 16 or 24 in (400 or 600 mm) centers, plus plates.
Yard, garden and exterior
Lawns, beds, gravel, fences, decks, pools and driveways.
Mulch CalculatorCubic yards, cubic meters and bag counts for garden beds at any depth.Gravel CalculatorCubic yards, tons and bags of gravel, crushed stone, sand or topsoil.Fence CalculatorPosts, rails and pickets for a wood picket or privacy fence.Deck CalculatorDeck boards, linear feet, joists and screws for a rectangular deck.Sod CalculatorSquare feet, rolls and pallets of sod for a new lawn, with waste for curves and edges.Grass Seed CalculatorPounds or kilograms of grass seed for a new lawn or overseeding, by grass type.Raised Bed Soil CalculatorCubic feet, cubic yards, liters and bags of soil to fill raised garden beds.Fertilizer CalculatorPounds or kg of lawn fertilizer to apply for a target amount of nitrogen.Pool Volume CalculatorGallons or liters in a rectangular, round or oval pool, with sloped bottoms.Asphalt CalculatorTons or tonnes of hot-mix asphalt for a driveway, path or parking pad.Rainwater Harvesting CalculatorGallons or liters of rainwater a roof can collect, and barrels to store it.
Latest guides
Straight answers to the questions people ask before they start. All guides
What Is the Best Soil Mix for Raised Beds?Yard, garden and exteriorWhat Do the Numbers on Fertilizer Mean?Yard, garden and exteriorHow Much Should You Lower Pool Water for Winter?Yard, garden and exteriorHow Thick Should an Asphalt Driveway Be?Yard, garden and exteriorHow Many Rain Barrels Do You Need?Yard, garden and exteriorSanded vs Unsanded GroutPaint, walls and floorsWhat Size Trowel Do I Need for Tile?Paint, walls and floorsHow to Measure for CarpetPaint, walls and floorsHow to Prepare a Garage Floor for EpoxyPaint, walls and floorsWhen Is the Best Time to Paint the Outside of a House?Paint, walls and floorsHow Long Does Deck Stain Take to Dry?Paint, walls and floorsTypes of Drywall Joint CompoundPaint, walls and floors
Nothing matches that yet. Try a material such as tile, fence or mulch.
How our numbers work
Each calculator uses the same method a contractor would: measure the area or volume, add a margin for waste, and round up to the units the store sells. Coverage, yield and weight figures come from product labels and common trade practice in the United States, Canada and Australia, and you can change them where your product differs. Read how we check our numbers.