Home & DIY
Plan home and DIY projects with confidence: estimate paint, flooring, tile, mulch, concrete and other materials, size an air conditioner, and more.
Appliance Energy Calculator
Find what an appliance costs to run from its wattage. Enter watts, hours per day and your rate to see kWh and cost per day, month and year.
Aquarium Volume Calculator
Calculate your fish tank volume in gallons and liters from inside dimensions in inches. Set a fill level to estimate the actual water it holds.
Baseboard Calculator
Estimate linear feet and pieces of baseboard or trim for a room. Enter length and width, subtract doorways, set piece length and add waste.
Battery Bank Calculator
Size an off-grid battery bank from your daily load. Enter watt-hours per day, days of autonomy, voltage, depth of discharge and efficiency.
Board Feet Calculator
Calculate board feet of lumber from thickness, width and length. Enter quantity and price per board foot to get total board feet and project cost.
Brick Calculator
Calculate how many bricks you need for a wall. Enter the wall size and brick size to get wall area, bricks before waste and bricks to buy with waste.
BTU Calculator
Calculate the air conditioner BTU size for a room. Enter the room size and adjust for sun, occupants and a kitchen to find the right cooling capacity.
Bucket Flow Rate Calculator
Measure your water flow rate with the bucket method. Enter the container size and seconds to fill to get gallons per minute, per hour and liters per minute.
CFM Calculator
Calculate the CFM airflow a room needs from its volume and air changes per hour. Enter the length, width, height and ACH to size ventilation.
Concrete Calculator
Calculate concrete for a slab or footing. Enter length, width and thickness to get cubic yards plus 60 and 80 lb bag counts, with a waste allowance.
Cutting List Calculator
Work out how many boards to buy to cut a list of pieces. Enter the piece length, quantity, stock length and saw kerf to get boards needed and offcut.
Deck Board Calculator
Calculate how many deck boards you need. Enter deck length and width, board size, the gap between boards and waste to get a deck board count.
Deck Calculator
Estimate deck boards, joists and screws for a deck. Enter length and width, set board size, gap and joist spacing, and add waste for cuts.
Deck Stain Calculator
Find how many gallons of deck stain or sealer you need. Enter the deck size, coats and railing length for the surface area and gallons to buy.
Dehumidifier Size Calculator
Find the dehumidifier pint capacity a damp space needs. Enter the area and dampness level for a DOE-style pints-per-day size recommendation.
Drain Slope Calculator
Calculate drain pipe slope and total fall. Enter the run length and slope to get the percent grade and total drop, with code defaults of 1/4 in per foot.
Drywall Calculator
Estimate sheets of drywall for a room, plus screws and joint compound. Enter wall area or room size and height, add the ceiling, and set waste.
Drywall Mud Calculator
Estimate joint compound for drywall. Enter drywall area and number of coats to get pounds of mud and how many premixed boxes you need to buy.
Duct Size Calculator
Size a round duct from CFM and air velocity. Enter airflow and feet per minute to get the cross-section in square inches and the equivalent diameter.
EV Charging Time Calculator
Estimate how long it takes to charge an electric car. Enter battery size, charger power and charge level to see hours and minutes.
Fence Calculator
Estimate posts, sections, rails and pickets for a fence. Enter total length and post spacing, set rails per section and picket width, and add gates.
Fertilizer NPK Calculator
Find how much fertilizer to apply for a target nitrogen rate. Enter area, target N per 1000 sq ft and the N percent to get pounds per 1000 and total.
Firewood Cord Calculator
Calculate how many cords of firewood are in a stack. Enter the length, height and depth to get the stack volume and cords, where a full cord is 128 cu ft.
Flooring Calculator
Find how many boxes of flooring you need for a room. Enter length, width, box coverage and waste to get square footage, boxes and total cost.
Furnace Size Calculator
Estimate the heating BTU and furnace size for a home by climate zone. Enter the area and efficiency to find the output and input BTU you need.
Generator Size Calculator
Find the generator size you need from running and starting watts. Add a safety headroom and see recommended watts and kilowatts.
Grass Seed Calculator
Find how many pounds of grass seed your lawn needs. Enter the area and choose new lawn or overseeding to get the seed weight at the right rate.
Gravel Calculator
Estimate gravel or aggregate for an area by volume and weight. Enter length, width, depth and density to get cubic feet, cubic yards, pounds and tons.
Heat Load Calculator
Estimate the cooling heat load and air conditioner BTU for a room. Adjust for square footage, occupants, sun and a kitchen to find the right size.
Insulation Calculator
Estimate bags of insulation for an area. Enter the square footage, or the length and width, set the coverage per bag and add a small waste allowance.
kWh Cost Calculator
Work out the cost of any amount of electricity. Enter kWh and your rate to get the price, plus monthly and yearly totals for daily usage.
Lawn Fertilizer Calculator
Find how many pounds of fertilizer to apply to hit a nitrogen rate. Enter the lawn area, target rate and the nitrogen percent on the bag to get the amount.
Lawn Watering Calculator
Find how much to water your lawn. Enter area and inches per week to get gallons per week, plus sprinkler run time when you add gallons per minute.
LED Savings Calculator
See how much you save by switching bulbs to LED. Enter old and new wattage, bulb count, hours and your rate for yearly and monthly savings.
Mulch Calculator
Find how much mulch you need for a garden bed. Enter length, width and depth to get cubic feet, cubic yards and the number of 2 and 3 cu ft bags.
Paint Calculator
Estimate how many gallons of paint you need for a room or wall. Enter dimensions, coats, doors and windows to get paintable area and gallons.
Paver Calculator
Find how many pavers and how much sand a patio needs. Enter the patio size, paver size and waste to get the paver count and sand in cubic yards.
Pipe Flow Rate Calculator
Calculate water flow rate in gallons per minute from pipe size and velocity. Enter the inner diameter and speed to get GPM and cubic feet per second.
Pipe Volume Calculator
Calculate the water volume held inside a pipe in gallons, liters and cubic inches. Enter the inner diameter and length to size flush and purge jobs.
Plant Spacing Calculator
Find how many plants fill a garden bed at a given spacing. Enter bed length, width and spacing to get plants, rows and columns for square or triangular layouts.
Pond Liner Calculator
Find the liner size for a garden pond. Enter the pond length, width, depth and overlap to get the liner dimensions, area and an estimated water volume.
Pool Chlorine Calculator
Calculate how much chlorine to add to your pool to raise free chlorine by a target ppm. Enter gallons, the ppm rise and product strength for the dose.
Pool Heater Calculator
Calculate the energy and time to heat your pool. Enter gallons, the temperature rise, heater output and efficiency to get BTU, kWh and heating hours.
Pool Salt Calculator
Calculate how much salt to add to reach a target salinity in your saltwater pool. Enter gallons, current ppm and target ppm to get pounds and kilograms.
Pool Turnover Calculator
Calculate your pool turnover time from the pump flow, or the flow rate needed for a target turnover. Enter gallons and one rate to size the pump.
Pool Volume Calculator
Calculate your swimming pool water volume in gallons and liters. Works for rectangular, circular and oval pools with shallow and deep end depths.
Post Hole Concrete Calculator
Work out concrete bags to set a post. Enter hole diameter and depth, post width, post count and bag yield for cubic feet per hole and bags to buy.
Rainwater Harvesting Calculator
Find how much rainwater you can collect from a roof. Enter roof area, rainfall and collection efficiency to get gallons and liters you can capture.
Raised Bed Soil Calculator
Find how much soil to fill a raised garden bed. Enter length, width and depth to get cubic feet, cubic yards and the number of soil bags to buy.
Rebar Calculator
Calculate rebar for a concrete slab grid. Enter slab length, width and bar spacing to get bars each way, total bars and total linear feet of rebar.
Retaining Wall Calculator
Calculate blocks for a retaining wall. Enter wall length and height plus block size to get blocks per course, courses, cap blocks and total blocks.
Roof Pitch Calculator
Calculate roof pitch from rise and run. Get the x:12 ratio, angle in degrees, slope factor and percent grade, plus rafter length for any horizontal run.
Roofing Squares Calculator
Convert roof area to roofing squares and shingle bundles. Enter roof area in square feet, set waste and bundles per square to get bundles needed.
Room Lighting Calculator
Find how many lumens and bulbs a room needs. Enter the room size, a target light level in foot-candles and your bulb output in lumens.
Seed Starting Date Calculator
Find when to start seeds indoors and transplant, based on your last frost date. Enter the frost date and weeks before and after to get exact dates.
SEER Savings Calculator
Estimate annual cooling cost and savings between two SEER ratings. Compare your current AC to a higher SEER system to see the yearly bill drop.
Shelf Sag Calculator
Calculate how much a loaded shelf will sag from its span, depth, thickness, load and material. See deflection per foot and whether it is acceptable.
Siding Calculator
Estimate siding squares and panels for exterior walls. Enter wall area, subtract doors and windows, set waste and panel coverage to get panels.
Sod Calculator
Estimate rolls and pallets of sod for a lawn. Enter length and width, set roll coverage and rolls per pallet, and add a waste allowance for cuts.
Soil Amendment Calculator
Find how much compost or amendment to top-dress a bed. Enter area and depth to get cubic feet, cubic yards and the number of bags to buy.
Solar Panel Calculator
Estimate how much electricity a solar array makes. Enter system size or panel specs, sun hours and losses for daily, monthly and yearly kWh.
Solar Payback Calculator
Find how many years until solar panels pay for themselves. Enter system cost, yearly production and your rate to see the payback period.
Square Footage Calculator
Calculate square footage for one room or many. Enter length and width in feet, inches, meters or yards to get total area in sq ft, sq m and sq yd.
Stair Calculator
Calculate stairs from a total rise. Get the number of steps, riser height, tread run, total run and stringer length for a safe, even staircase.
Tile Calculator
Calculate how many tiles you need for a floor or wall. Enter the area and tile size with a waste allowance to get tiles and boxes to buy.
Topsoil Calculator
Calculate how much topsoil you need for a garden bed. Enter length, width and depth to get cubic yards, cubic feet, bags and approximate weight.
UPS Runtime Calculator
Estimate UPS battery runtime under load. Enter battery watt-hours or volts and amp-hours plus the load in watts to see minutes and hours.
Wallpaper Calculator
Work out how many rolls of wallpaper you need for a wall. Enter wall size, roll size and pattern repeat to get strips per roll and rolls to buy.
Water Heater Cost Calculator
Find the energy and cost to heat a tank of water. Enter gallons, inlet and outlet temperature, your rate and efficiency to get kWh and cost.
Water Heater Recovery Calculator
Calculate a water heater recovery rate in gallons per hour from its BTU input, efficiency and temperature rise. See how fast it reheats a full tank.
Water Pressure Loss Calculator
Estimate friction pressure loss in a water pipe using the Hazen-Williams formula. Enter flow, pipe size and length to see psi lost per 100 ft and total.
Watt Hour Calculator
Convert volts and amp-hours, or watts and hours, into watt-hours. See energy in Wh, kWh and mAh for batteries and devices.
Wood Finish Coverage Calculator
Work out how much stain, paint or polyurethane a project needs. Enter the surface area, coats and finish type to get gallons and quarts required.
Wood Shrinkage Calculator
Estimate how much a board shrinks or swells as moisture content changes. Enter width, start and target moisture, then a species and saw cut.