Figure out how much you need.
Free calculators for home, yard and DIY projects. Every formula is tested, every material figure is sourced, and every page is reviewed before it goes live.
Concrete & Masonry
All concrete & masonry →- Asphalt CalculatorEstimate how many tons of hot mix asphalt a driveway, parking pad or pothole needs, with cubic yards and bags of cold patch.
- Brick CalculatorWork out how many bricks to buy for a single-layer brick wall or veneer, with extra for breakage and the bags of mortar mix to lay them.
- Concrete Block CalculatorWork out how many concrete blocks to buy for a wall, from its length, height and openings, with extra for waste and the bags of mortar mix.
- Concrete CalculatorWork out how much concrete you need for a slab, footing or column in cubic yards, cubic feet and bags of pre-mixed concrete, with extra for waste.
- Concrete Slab CalculatorEstimate cubic yards and bags of concrete for a patio, shed base, garage floor or driveway slab, including extra for waste and a thickened edge.
- Sonotube Concrete CalculatorWork out the concrete for round column forms and post footings from diameter, height and count, in cubic feet, cubic yards and bags.
- Concrete Weight CalculatorFind the weight in pounds and tons of a concrete slab, block or column from its size, for planning hauling, trailer loads, demolition and lifting.
- Gravel CalculatorEstimate how much gravel a driveway, path, patio base or drainage trench needs, in tons, cubic yards and bags of all-purpose gravel.
- Mortar CalculatorEstimate how many bags of pre-mixed mortar a brick or concrete block wall needs, from its length, height and openings, with extra for waste.
- Paver CalculatorWork out the pavers for a patio or walk, plus the base gravel, bedding sand, polymeric sand and edge restraint, with the extra for cuts one paver maker adds.
- Pea Gravel CalculatorEstimate pea gravel for a garden path, seating pad, plant bed or tree ring in cubic yards, tons and bags, with notes on edging.
- Rebar CalculatorWork out the rebar for a concrete slab: bars each way at your spacing, the bars to buy with laps, total length, weight, ties and chairs.
- Retaining Wall CalculatorWork out the blocks, caps and gravel for a segmental block retaining wall, with the buried course, leveling pad and drainage gravel the block makers call for.
- Sand CalculatorEstimate sand for a sandbox, paver bedding, play area or leveling layer under a pool or shed, in tons, cubic yards and bags.
Landscaping & Garden
All landscaping & garden →- Compost CalculatorEstimate compost for lawn top dressing, garden beds, trees and shrubs, and erosion control, in cubic yards and cubic feet.
- Fertilizer CalculatorWork out how many pounds of lawn fertilizer to spread for a set nitrogen rate, from the size of your lawn and the first number on the bag.
- Fill Dirt CalculatorEstimate how much fill dirt a low spot, raised grade or trench backfill needs in cubic yards, with an allowance for soil that packs down.
- Firewood CalculatorFind how many cords or face cords are in a stack of firewood, how much solid wood that is, and how much heat it holds by species, from NIST and extension data.
- Raised Garden Bed Soil CalculatorFind the soil volume for any number of raised garden beds, with depth by crop, in cubic yards, cubic feet and bags of soil.
- Grass Seed CalculatorWork out how many pounds of grass seed a lawn needs for a new lawn or overseeding, from its length and width and the grass you choose.
- Mulch CalculatorWork out how much mulch to buy for beds, tree rings and borders, in cubic yards and bags, with depth guidance and a top-up option.
- Plant Spacing CalculatorFind how many plants fit in a bed at your spacing, in a square grid or staggered rows, with spacings for common vegetables from an extension guide.
- River Rock CalculatorWork out how much river rock or landscape rock you need for a bed, path or dry creek: cubic yards, tons and bags, for any shape and depth.
- Sod CalculatorWork out the square feet of sod to order for a lawn, yard or side strip, plus the pieces and pallets, with extra for cuts.
- Soil CalculatorEstimate how much topsoil or garden soil to order for new beds, leveling and lawn areas, in cubic yards, cubic feet and bags.
Lumber & Framing
All lumber & framing →- Board Feet CalculatorWork out the board feet of framing, deck or shelf lumber from nominal thickness, width and length, with total length and cost at your price.
- Plywood CalculatorFind how many sheets of plywood or OSB you need for a roof, walls or a floor, what they weigh, the thinnest panel the code allows, and the nails to buy.
- Stair CalculatorPlan a whole staircase before any lumber is cut: count the steps, size each riser, find the total run across the floor and check the code limits.
- Stair Stringer CalculatorWork out risers, riser height, treads, total run, stringer length and stair angle for deck, porch or basement stairs from the total rise.
- Stud CalculatorWork out how many studs a wall needs from its length and on-center spacing, with extra for corners and openings and the plate lumber to buy.
- Wood Weight CalculatorFind the weight of lumber, boards, slabs, logs or board feet for over thirty wood species, dry or freshly cut, from the USDA Wood Handbook.
Drywall, Paint & Walls
All drywall, paint & walls →- Board and Batten CalculatorLay out a board and batten accent wall with even spacing, or board and batten siding with a batten over every gap, and get the boards to buy.
- Drop Ceiling CalculatorPlan a suspended ceiling: the panels, main tees, cross tees, wall molding and hanger wires for your room, laid out with even border panels.
- Drywall CalculatorWork out how many drywall sheets to buy for a room, from wall and ceiling area, openings and extra for waste, with a rough screw count.
- Drywall Mud CalculatorWork out how many gallons of joint compound and feet of paper tape a drywall job needs, with the pails and rolls to buy, from the drywall area.
- Paint CalculatorWork out how many gallons of wall paint to buy for a room from its size, wall height and openings, with ceiling paint and primer when you need them.
- Siding CalculatorEstimate siding for a house in squares, vinyl cartons or fiber cement planks, from the wall length and height, the gables, and the doors and windows.
- Wainscoting CalculatorWork out the beadboard sheets or tongue-and-groove planks for wainscoting, plus the cap rail, baseboard, adhesive and nails, from your wall length and height.
- Wallpaper CalculatorWork out how many rolls of wallpaper to buy for a room from its size, wall height and pattern repeat, for US double rolls or European rolls.
Flooring & Tile
All flooring & tile →- Carpet CalculatorWork out how much carpet to buy for a room in square yards, with the full roll width of every strip and extra for patterned carpet.
- Flooring CalculatorWork out how much plank flooring to buy for a room from its length and width, with extra for cuts and the number of boxes for laminate, vinyl or hardwood.
- Grout CalculatorWork out how many pounds of grout and bags a tiled floor or wall needs, from the area, the tile size, the joint width and the tile thickness.
- Laminate Flooring CalculatorWork out how many boxes of laminate flooring to buy for a room from its length, width and the coverage on your carton, with extra for cuts.
- Tile CalculatorWork out how many floor or wall tiles to buy for a room, shower or backsplash from the area and the tile size, with extra for cuts and spares.
Roofing
All roofing →- Attic Ventilation CalculatorWork out the net free vent area an attic needs from its length and width, then split it evenly between low intake and high exhaust vents.
- Gutter Fall CalculatorWork out how far a gutter run drops from its high end to the downspout, and how much it drops per foot, so water runs toward the outlet.
- Metal Roofing CalculatorWork out the metal roofing panels, their cut length, the screws and the ridge, eave and rake trim for a gable or shed roof, from makers' installation guides.
- Rafter CalculatorWork out rafter length, run and ridge height for a gable roof from the building width, the pitch and the overhang before you cut lumber.
- Roof Pitch CalculatorWork out a roof's pitch from its rise and run, with the angle in degrees, the slope in percent and the slope multiplier for the roof surface.
- Roof Square CalculatorWork out the roof surface and roofing squares from a roof's footprint and pitch, with extra for waste, so you know how much shingle to order.
- Roofing CalculatorEstimate roofing squares, roof surface area and bundles of shingles from a roof's footprint and pitch, with extra for waste.
- Shingle CalculatorWork out how many bundles of shingles to buy from a roof's footprint, pitch and extra for waste, with the roofing squares and roof surface.
Fences & Decks
All fences & decks →- Deck CalculatorCount the deck boards, rows of boards and joists for a wood or composite deck from its length, width, board width and joist spacing.
- Deck Spindle Spacing CalculatorWork out how many deck balusters, also called spindles, to fit between posts so every gap stays under your limit, with even spacing and totals.
- Deck Step CalculatorWork out the risers, riser height, treads, total run and stringer length for deck steps, measured from the top of the decking to the landing.
- Fence CalculatorWork out the posts, rails and pickets for a fence from its length and post spacing, with gates, equal sections and the actual post spacing.
- Fence Post Depth CalculatorWork out the hole depth, hole diameter, post length to buy and concrete bags for each fence post from its height above ground and actual width.
- Picket Fence CalculatorCount the pickets for a fence run from its length, picket width and gap, plus the posts, sections and rails you need.
- Ramp CalculatorWork out the ramp run, surface length, landings and slope for a wheelchair ramp from its total rise, using the ADA slope and landing limits.
Pool, Pond & Aquarium
All pool, pond & aquarium →- Aquarium CalculatorWork out how many gallons your fish tank holds, for rectangle, bow front, cylinder or hexagon tanks, what the water weighs, and the heater size it needs.
- Aquarium Substrate CalculatorFind how many pounds of aquarium gravel, sand, crushed coral or planted-tank substrate to buy for your tank and bed depth, and how many bags that is.
- Pond Liner CalculatorWork out the pond liner size you need from the pond's length, width and deepest point, with an edge to bury all round and underlayment to match.
- Pond Volume CalculatorFind how many gallons your garden pond holds, for any shape, then the pump flow it needs, with a waterfall, and how many fish it can keep.
- Pool Chemical CalculatorWork out how much liquid chlorine, cal hypo, baking soda, muriatic acid, calcium chloride or stabilizer to add to your pool, from state dosage charts.
- Pool Salt CalculatorFind how many pounds and bags of salt your saltwater pool needs to reach the level your chlorine generator's maker recommends, or how much to drain.
- Pool Volume CalculatorFind the water volume of a rectangular, round or oval pool in gallons, liters and cubic feet, using the average depth of a sloped floor.
- Water Usage CalculatorEstimate your household's water use a day, month and year by use, from EPA's survey of US homes, with efficient fixtures and lawn watering.
- Well Volume CalculatorFind how many gallons of water are in your well from its casing size and depth, and how much bleach to shock chlorinate it, from state extension guides.
Area & Volume
All area & volume →- Cubic Feet CalculatorFind the volume of a box, room, closet or round container in cubic feet, cubic yards, cubic meters and US gallons, using any unit.
- Cubic Yard CalculatorConvert length, width and depth into cubic yards, cubic feet and cubic meters for soil, mulch, gravel or sand, with an optional cost per yard.
- Epoxy CalculatorWork out the epoxy resin to mix for a river table, a mold or a coating, in gallons, quarts and ounces, with extra to mix and the depth per pour.
- Pipe Volume CalculatorWork out the gallons a pipe holds from its size and length, for PVC Schedule 40, PVC Schedule 80 or any pipe by its inside diameter, plus the weight.
- Square Footage CalculatorFind the square feet of a room, floor, patio or lot of any shape. Add several areas, subtract cut-outs, and see square yards, square meters and acres.
- Steel Weight CalculatorFind the weight of steel plate, bar, tube, pipe or angle from its size, and of stainless steel, aluminum, copper, brass or cast iron, in pounds and per foot.
- Tank Volume CalculatorWork out how many gallons, liters or cubic feet a round, lying or rectangular tank holds, and how full it is at a set liquid depth.
- Water Weight CalculatorFind how much water weighs from gallons, liters or cubic feet, cold, hot or boiling, plus seawater and ice, from USGS and NOAA density figures.
DIY Build Plans
All diy build plans →- Bat House PlansFree bat house plans after Bat Conservation International's proven design: a cut list, a shopping list, a drawing for every step, and where to mount it.
- Bird House PlansFree bird house plans for bluebirds, wrens, chickadees, swallows, kestrels and screech-owls, with the right hole, box size and mounting height for each.
- Chicken Coop PlansFree chicken coop plans sized to your flock and your yard: a shopping list, a cut list with cutting diagrams, and step-by-step drawings for every screw.
- Picnic Table PlansFree picnic table plans for a classic six- or eight-foot table with attached benches: a cut list, shopping list, bolt pattern and a drawing for every step.
- Raised Garden Bed PlansFree raised garden bed plans that fit your yard: beds sized to your space, a shopping list, a cut list with cutting diagrams and step-by-step drawings.
- Shed PlansFree gable shed plans sized to you, from 6x6 to 12x16: pick the size, door and roof pitch, and get the shopping list, cut list and a drawing for every step.
Electrical, Heating & Insulation
All electrical, heating & insulation →- Amp CalculatorConvert watts, kilowatts, horsepower or kVA to amps for DC, single-phase and three-phase circuits, with power factor and motor efficiency taken into account.
- BTU Calculator for Room Air ConditionersEstimate the BTU per hour a window or portable air conditioner needs for a room, using its floor area, sun, occupants and kitchen use.
- Ceiling Fan Size CalculatorFind the right ceiling fan size for your room from ENERGY STAR's sizing table, and how high to hang it for your ceiling, from flush mounts to tall ceilings.
- CFM CalculatorSize a bathroom fan, a range hood or the airflow for any room in cubic feet per minute, using the Home Ventilating Institute's rules and the code minimums.
- Conduit Fill CalculatorCheck conduit fill for THHN wire in EMT, PVC, rigid or flexible conduit: the percent fill, the most wires that fit and the smallest trade size that works.
- Electricity Cost CalculatorWork out the kWh a device uses and what it costs per day, month and year from its watts, hours of use, days per week and your price per kWh.
- Generator Size CalculatorFind the generator size you need from the appliances you want to run: running watts, the starting surge of the biggest motor, and a margin on top.
- Heat Loss CalculatorEstimate your home's heat loss in BTU per hour through the walls, windows, ceiling, floor and air leaks, at your design temperature, to size heating.
- Insulation CalculatorFind the R-value ENERGY STAR recommends for your attic or floor and climate zone, the depth that gives it, and the bags of blown-in insulation to buy.
- R-Value CalculatorAdd up the R-value of a framed wall layer by layer, and see the whole-wall R-value once the studs are counted, with batts, blown-in, spray foam and rigid foam.
- Recessed Lighting CalculatorPlan recessed lights for a room: how many, how far apart and how far from the walls, with a check that they give enough light for the room.
- Solar Panel Angle CalculatorFind the best tilt for your solar panels from your latitude: year-round, summer and winter, month by month, and as a roof pitch, plus which way to face them.
- Voltage Drop CalculatorWork out the voltage drop on copper or aluminum wire for DC, single-phase and three-phase circuits, and find the smallest AWG size for your run.
- Water Heater Size CalculatorSize a water heater the Department of Energy way: a tank by its first-hour rating from your busiest hour, a tankless heater by flow and temperature rise.
- Wire Size CalculatorFind the wire gauge for a circuit from its current, voltage and run length, with ampacity and voltage drop checked together, for copper and aluminum.
Data guides
All data guides →- Air Conditioner Size Chart: How Many BTU for Your RoomThe ENERGY STAR room air conditioner sizing chart, its adjustments for sun, people and kitchens, and the BTU size for common room sizes worked out from it.
- AWG Wire Resistance Chart, with Voltage Drop DistancesDC resistance per 1,000 ft and per km for copper and aluminum wire by AWG size, and how far each size can run before the voltage drop passes the usual limit.
- How Much Concrete Does a Bag Make? Yields and Bags per YardPublished yields for every common bag size of Quikrete and Sakrete concrete, the bags needed per cubic yard, and bag counts for small jobs.
- How Much Does a Sheet of Drywall Weigh? Weights by Thickness and BrandPublished weights for drywall from USG, Gold Bond, CertainTeed and Georgia-Pacific, by thickness, with what a 4x8 or 4x12 sheet weighs.
- Grass Seed Rates by Grass Type, From University ExtensionsSeeding rates for bluegrass, fescue, ryegrass, bermuda, zoysia and centipede from university extension services, side by side, for new lawns and overseeding.
- How Much Does a Cubic Yard Weigh? Gravel, Sand, Soil, Mulch and MorePublished weights per cubic yard for gravel, sand, soil, mulch, compost, crushed stone and concrete, loose and compacted, from state DOT and EPA tables.
- How Many Bricks or Blocks Does a Bag of Mortar Lay?Published yields for pre-mixed mortar and masonry cement from Quikrete, Sakrete and Spec Mix, side by side, with what each figure includes.
- How Many Bundles of Shingles Make a Square? By Brand and ProductBundles per square, coverage and shingle counts for Owens Corning, CertainTeed, IKO, TAMKO and GAF shingle lines, copied from each maker's data sheet.