100 free calculators · US, UK & Australia
Plan it. Measure it. Build it.
Every home improvement calculation in one place — flooring, paint, concrete, roofing, plumbing, energy and more. Real formulas, metric and imperial units, wastage included, and no invented prices. Type a measurement, get a quantity you can shop with.
- 100 calculators
- 10 categories
- 0 prices invented
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Browse by category
Ten sections, one hundred calculators.
Flooring & Tiles
10 calculators
Tiles, flooring and grout — measure the room, get boxes and cost.
Browse Flooring & Tiles →Concrete & Construction
10 calculators
Concrete, gravel, sand, brick and mortar — volumes, bags and mixes.
Browse Concrete & Construction →Painting & Walls
10 calculators
Paint, primer, wallpaper and drywall — litres, rolls and sheets.
Browse Painting & Walls →Garden & Landscaping
10 calculators
Mulch, soil, lawn seed, sod and paving — volumes and coverage.
Browse Garden & Landscaping →Roofing & Exterior
10 calculators
Roofing, shingles, gutters, siding, fences and decks.
Browse Roofing & Exterior →Home Renovation & Cost
10 calculators
Renovation, kitchen and bathroom costs, labour, budgets and timelines.
Browse Home Renovation & Cost →Measurements & Conversions
10 calculators
Areas, volumes and unit conversions — ft², m², yd³, litres and more.
Browse Measurements & Conversions →Plumbing & Water
10 calculators
Pipes, tanks, flow, pressure, pools and plumbing costs.
Browse Plumbing & Water →Electrical & Energy
10 calculators
Electricity costs, solar, batteries, generators and heating.
Browse Electrical & Energy →Doors, Windows & Interior
10 calculators
Windows, doors, stairs, railings, insulation and storage.
Browse Doors, Windows & Interior →Most popular calculators
See all 100 →Tile Calculator
Tiles and boxes for any floor or wall, with grout and wastage.
Open calculator →Paint Calculator
Litres and tins for any room, with coats and coverage.
Open calculator →Concrete Calculator
Volume, bags and ready-mix for slabs, footings and driveways.
Open calculator →Flooring Calculator
Boards, planks and boxes for the whole room, with cost.
Open calculator →Square Footage Calculator
The area of any room in ft², m², yd² and acres.
Open calculator →Kitchen Remodel Calculator
The full kitchen budget — cabinets to labour, with tax.
Open calculator →Roofing Calculator
Squares, underlayment and bundles for any roof.
Open calculator →Mulch Calculator
Cubic yards of mulch for any bed, at any depth.
Open calculator →Wallpaper Calculator
Rolls and strips for any wall, with pattern repeat.
Open calculator →Electricity Cost Calculator
Your bill from kWh and tariff, plus the standing charge.
Open calculator →Featured DIY guides
All guides →How to Measure a Room for Flooring
Measuring a room for flooring takes ten minutes and a tape measure — and it is the difference between ordering enough and ordering twice. Here is the method, step by step.
How Much Paint Do I Need?
Paint is sold by coverage, not by room — so the answer is wall area divided by coverage, times the coats. Here is how to work it out without guessing.
How to Estimate Concrete for a Slab
Concrete is ordered by volume — cubic yards or cubic metres — and the volume is length times width times depth. Here is how to get it right the first time.
How to Plan a Kitchen Remodel Budget
A kitchen budget is a list, not a number — cabinets, worktops, appliances, flooring, plumbing, electrics and labour, plus a contingency for the surprises. Here is how to build it.
How to Estimate Solar Panel Output
Solar output is three numbers multiplied together: system size, peak sun hours and efficiency. Here is what each one means and how to find yours.
How to Measure Stairs and Railings
Stairs are measured by rise and run — and the rule is that every riser must be equal. Here is how to measure a flight and its railing.
All calculators
Every calculator on the site, grouped by phase.
Phase 1 — Flooring & Tiles (10 calculators)
Tiles
Tile Calculator
Find out exactly how many tiles to buy for any floor or wall — with a cutting and breakage allowance included, so you do not run short mid-job.
TilesTile Square Foot Calculator
Work out the square footage of tile a room needs — in square feet, square metres and square yards — and how many tiles that means once cutting waste is added.
TilesShower Tile Calculator
Work out how many tiles a shower needs — three tiled walls plus the floor — with the shower door deducted and a realistic allowance for cuts around the drain, niches and corners.
TilesBacksplash Calculator
Work out how many backsplash tiles a kitchen or bathroom needs — with power outlets deducted and a 15% allowance for the many small cuts around edges and sockets.
TilesGrout Calculator
Work out exactly how much grout a tiled area needs — in kilograms and bags — from the tile size, joint width and joint depth. No guessing, no wasted bags.
Flooring
Flooring Calculator
Work out how many boxes of flooring a room needs — any type sold by the box — from the room size, the coverage printed on the box, and a cutting allowance.
FlooringCarpet Calculator
Work out how much carpet a room needs — in square yards for pricing, and in linear feet off the roll for ordering — including seams, pattern matching and cutting waste.
FlooringHardwood Flooring Calculator
Work out how many hardwood planks and boxes a room needs — with a cutting allowance for end cuts and damaged boards — and what the timber will cost at your price.
FlooringLaminate Flooring Calculator
Work out how many laminate planks and boxes a room needs — plus the underlay to go beneath them — with a cutting allowance and an optional cost estimate.
FlooringVinyl Flooring Calculator
Work out how much vinyl flooring a room needs — luxury vinyl planks (LVT/LVP) by plank and box, and sheet vinyl by the roll — with a cutting allowance for each.
Phase 2 — Concrete & Construction (10 calculators)
Concrete
Concrete Calculator
Work out how much concrete any rectangular pour needs — in cubic feet, cubic metres and cubic yards — and how many bags of ready-mix that means.
ConcreteConcrete Slab Calculator
Work out everything a concrete slab needs — volume, bags or ready-mix, and reinforcement mesh sheets — from the slab size and thickness.
ConcreteConcrete Volume Calculator
Work out the volume of concrete for a rectangular pour or a round pier — in cubic feet, cubic metres and cubic yards — and how many bags that volume takes.
ConcreteConcrete Footing Calculator
Work out how much concrete a set of footings needs — the volume of one footing, the total for all of them, and the bag count — for decks, posts and foundations.
ConcreteConcrete Driveway Calculator
Work out how much concrete a driveway needs — the ready-mix volume to order, the gravel sub-base beneath it, and the cost at your price per cubic yard.
Aggregates
Gravel Calculator
Work out how much gravel a path, driveway or sub-base needs — volume in cubic yards and metres, and weight in tons and tonnes for ordering by weight.
AggregatesSand Calculator
Work out how much sand a bed, base or fill needs — volume, weight and bag count — from the area and depth, with wastage included.
Masonry
Brick Calculator
Work out how many bricks a wall needs — with the mortar joints counted properly, wastage added, and single or double skin — for US and UK brick sizes.
MasonryBlock Calculator
Work out how many concrete blocks a wall needs — with mortar joints and wastage counted — for US 16×8 in blocks and UK 440×215 mm blocks.
MasonryMortar Calculator
Work out how much mortar a brick wall needs — volume and premix bags — from the wall size and brick size, using the exact wall-minus-brick method.
Phase 3 — Painting & Walls (10 calculators)
Painting
Paint Calculator
Work out how much paint any area needs — from the area, the number of coats, and your paint's own coverage. No two paints cover the same, so coverage is yours to enter.
PaintingWall Paint Calculator
Work out how much paint the walls of a room need — doors and windows deducted, coats counted, and your paint's own coverage used.
PaintingCeiling Paint Calculator
Work out how much paint a ceiling needs — from the room size, the number of coats, and your ceiling paint's coverage.
PaintingWallpaper Calculator
Work out how many wallpaper rolls a room needs — strips from the perimeter, strip length with the pattern repeat, and rolls to buy.
PaintingWall Area Calculator
Work out the exact paintable wall area of a room — doors and windows deducted, ceiling optional — in square feet, square metres and square yards.
PaintingPrimer Calculator
Work out how much primer the walls of a room need — area with openings deducted, coats, and your primer's own coverage.
PaintingPaint Cost Calculator
Work out what painting a room will cost — paint and primer quantities at the prices you enter, from the room size or an area you already know.
Drywall
Drywall Calculator
Work out how much drywall a room needs — wall and ceiling area, sheets with a cutting allowance, and the screws to fix them.
DrywallDrywall Mud Calculator
Work out how much joint compound (mud) a drywall job needs — litres, gallons and buckets — for a standard 3-coat taped finish.
DrywallDrywall Sheet Calculator
Work out how many drywall sheets any area needs — from the total area and the sheet size, with a cutting allowance and the offcut area shown.
Phase 4 — Garden & Landscaping (10 calculators)
Garden
Mulch Calculator
Work out how much mulch a bed or border needs — from the area and depth, in cubic yards and bags, with your own bag size.
GardenSoil Calculator
Work out how much soil a bed or planter needs — from the area and depth, in cubic yards and bags, with your own bag size.
GardenTopsoil Calculator
Work out how much topsoil a job needs — volume in cubic yards and weight in tonnes, with the density set from your supplier's figure.
GardenLawn Seed Calculator
Work out how much grass seed a lawn needs — from the area and your product's own coverage, for a new lawn or for overseeding.
GardenSod Calculator
Work out how much sod (turf) a lawn needs — rolls and pallets, with a cutting allowance, from your supplier's roll and pallet sizes.
GardenPaving Calculator
Work out how many paving stones a patio or path needs — with joints and wastage counted — plus the bedding sand underneath.
GardenGarden Bed Calculator
Work out how much soil raised garden beds need — from the bed size and the number of beds, in cubic yards and bags.
GardenLandscape Rock Calculator
Work out how much landscape rock a bed or border needs — volume in cubic yards and weight in tonnes, with the density set from your supplier's figure.
GardenPea Gravel Calculator
Work out how much pea gravel a path or border needs — volume, weight and bags, with the density set from your supplier's figure.
GardenCompost Calculator
Work out how much compost a bed or border needs — from the area and spread depth, in cubic yards and bags, with your own bag size.
Phase 5 — Roofing & Exterior (10 calculators)
Roofing
Roofing Calculator
Work out how much roofing a roof needs — surface area from the footprint and pitch, roofing squares with wastage, and underlayment rolls.
RoofingRoof Shingle Calculator
Work out how many shingle bundles a roof needs — from the footprint, pitch and your manufacturer's bundle coverage.
RoofingRoof Pitch Calculator
Work out a roof's pitch from rise and run — pitch per 12, slope angle, slope factor, and the roof area from the footprint.
RoofingRoof Area Calculator
Work out the true surface area of a roof — from the footprint and pitch, with up to three sections for L-shaped or multi-part roofs.
RoofingMetal Roofing Calculator
Work out how many metal roofing panels a gable roof needs — slope length, panels per slope, and the total with wastage.
Exterior
Gutter Calculator
Work out how much guttering a roof needs — total length and the number of downspouts, from the eave length and spacing.
ExteriorSiding Calculator
Work out how much siding a house needs — wall area with openings deducted, boxes from your product's coverage, and wastage.
ExteriorFence Calculator
Work out how much fencing a run needs — panels, posts and rails, from the fence length and your panel width.
ExteriorDeck Calculator
Work out how much decking a deck needs — boards from the size, width and gap, and joists from the spacing.
ExteriorDriveway Calculator
Work out what a driveway needs by its surface — asphalt or gravel by weight, concrete by volume and bags, or pavers by count.
Phase 6 — Home Renovation & Cost (10 calculators)
Renovation
Home Renovation Cost Calculator
Work out what a whole-home renovation will cost — your costs per category, plus a contingency and tax, with nothing priced by the site.
RenovationKitchen Remodel Calculator
Work out what a kitchen remodel will cost — line by line, with a contingency and tax, and the cost per square foot when you add the area.
RenovationBathroom Remodel Calculator
Work out what a bathroom remodel will cost — line by line, with a contingency and tax, and the cost per square foot when you add the area.
RenovationRoom Renovation Calculator
Work out what renovating one room will cost — from the room size and your line items, with contingency, tax and cost per square foot.
RenovationHome Improvement Budget Calculator
Work out whether your home improvement budget covers the job — your budget against your estimate, with the remainder and the percent used.
Cost
Labor Cost Calculator
Work out what labour will cost — workers, hours, overtime and the payroll burden, from your own rates.
CostMaterial Cost Calculator
Work out what materials will cost — up to five lines of quantity times price, with wastage and tax, from your own prices.
CostContractor Profit Calculator
Work out a contractor's price and profit — markup on cost, profit, and margin on price, with the difference explained.
CostCost Per Square Foot Calculator
Work out the cost per square foot of a project — from the total cost and the area, in dollars per ft², m² and yd².
CostProject Timeline Calculator
Work out how long a project will take — up to four tasks with durations and dependencies, with start and finish days for each.
Phase 7 — Measurements & Conversions (10 calculators)
Measurements
Square Footage Calculator
Work out the square footage of any area — rectangle, circle or a known area — in square feet, square metres, square yards and acres.
MeasurementsSquare Meter Calculator
Work out an area in square metres — from length and width in metres, feet or inches — with square feet, yards and hectares alongside.
MeasurementsCubic Yard Calculator
Work out a volume in cubic yards — from length, width and depth — with cubic feet and cubic metres alongside.
MeasurementsCubic Feet Calculator
Work out a volume in cubic feet — from length, width and depth — with cubic yards, cubic metres, litres and US gallons alongside.
Converters
Feet to Meters Converter
Convert feet to metres — exactly, with centimetres, millimetres, inches and yards alongside.
ConvertersInches to Feet Converter
Convert inches to feet — decimal feet, feet and inches, metres and centimetres, all from one number.
ConvertersArea Converter
Convert any area unit to any other — square feet, square metres, square yards, acres and hectares, with exact constants.
ConvertersVolume Converter
Convert any volume unit to any other — cubic feet, cubic yards, cubic metres, litres, US gallons and UK gallons.
ConvertersLength Converter
Convert any length unit to any other — inches, feet, yards, miles, millimetres, centimetres, metres and kilometres.
Cost
Phase 8 — Plumbing & Water (10 calculators)
Plumbing
Pipe Volume Calculator
Work out how much water a pipe holds — from its inner diameter and length — in litres, US gallons, UK gallons and cubic metres.
PlumbingWater Flow Calculator
Work out how much water flows in a given time — from the flow rate and the time — in litres, US gallons and cubic metres.
PlumbingWater Tank Calculator
Work out a water tank's capacity — rectangular or cylindrical — in litres, US gallons and cubic metres, with the usable volume at your fill level.
PlumbingPipe Size Calculator
Work out the pipe inner diameter a flow rate needs — and check the water velocity in an existing pipe — from flow rate and maximum velocity.
PlumbingDrainage Slope Calculator
Work out a drain's fall and slope — from the length and the fall, or the length and the slope — as a percentage and as a gradient.
PlumbingPipe Length Calculator
Work out how much pipe to buy — straight length plus elbow allowances and wastage — and how many standard pipe lengths that means.
Water
Hot Water Usage Calculator
Estimate how much hot water a household uses in a day — showers, baths, basin use and appliances — in litres and US gallons.
WaterWater Pressure Calculator
Convert water pressure between bar, psi, kPa, MPa and atmospheres — and see the equivalent head of water in metres and feet.
WaterPool Volume Calculator
Work out a swimming pool's volume — rectangular, circular or irregular — from its dimensions and average depth, in cubic metres, litres and gallons.
Cost
Phase 9 — Electrical & Energy (10 calculators)
Energy
Electricity Cost Calculator
Work out what your electricity costs — energy used times your tariff, plus the standing charge — in total and per day.
EnergyEnergy Usage Calculator
Work out how much energy your appliances use — up to three, with watts and hours per day — in kWh and in cost at your tariff.
EnergyWatt to kWh Calculator
Convert watts to kilowatt-hours — per day, per month and per year — with the cost at your tariff.
EnergyLighting Calculator
Work out how much light a room needs — from its size and your target light level — in lumens, bulbs and watts.
EnergySolar Panel Calculator
Estimate what a solar system produces — from its size, your sun hours and its efficiency — in kWh per day, month and year.
EnergyBattery Backup Calculator
Work out the battery you need for a backup — from the load and the hours — in amp-hours, or see how long a battery you have will last.
EnergyGenerator Size Calculator
Work out the generator size you need — from your loads and their starting multipliers — in running watts, starting watts, kW and kVA.
EnergyVoltage Calculator
Work out voltage, current, resistance and power — from any two known values, with Ohm's law.
EnergyAmps to Watts Calculator
Convert amps to watts — or watts to amps — from the voltage, in watts, kilowatts and amps.
EnergyRoom Heating Calculator
Work out the heating a room needs — from its size, the temperatures and the insulation — in watts, kilowatts and BTU per hour.
Phase 10 — Doors, Windows & Interior (10 calculators)
Windows
Window Cost Calculator
Work out what your windows cost — from the count, the size and your prices — with the total area, material cost, install cost and total.
WindowsWindow Area Calculator
Work out the total area of your windows — and how much of it is glass — from the count, the size and the frame percentage.
Doors
Stairs
Stair Calculator
Work out a staircase — from the total rise and your riser height — in steps, actual riser, total run and angle.
StairsRailing Calculator
Work out a railing's quantities — from its length and your spacings — in balusters, posts and total length.
Interior
Insulation Calculator
Work out how much insulation you need — from the area and the coverage per pack — in packs and in cost.
InteriorRoom Size Calculator
Work out a room's size — from its length, width and height — in floor area, wall area, volume and perimeter.
InteriorFurniture Space Calculator
Check whether your furniture fits — from the room size and the pieces — with the free area, the free percentage and a walkway check.
InteriorCabinet Material Calculator
Work out the board for your cabinets — from the count, the dimensions and the shelves — in board area, sheets and edge banding.
InteriorCloset Space Calculator
Plan a closet — from its size, the rod levels and the shelves — in hanging length, shelf area, storage volume and garment capacity.
How the calculators work
- Real formulas. Every formula is shown on its calculator page, with a worked example you can check by hand.
- Metric and imperial. Switch between feet/inches and metres/millimetres at the top of any calculator — no re-typing.
- Wastage included. Cutting and breakage allowances are applied before rounding up, so you buy enough without buying far too much.
- Your prices only. Cost estimates appear only when you enter a price. This site publishes no prices.
- Private by design. Calculations run in your browser. Nothing you type is sent anywhere.
Not sure where to start?
Most projects start with a measurement. Try the square footage calculator for the room, then the calculator for the job — paint, flooring, concrete or roofing.
About this site
This is a 100-calculator home improvement platform, built in phases. All 10 phases are complete — 100 calculators in total: flooring and tiles, concrete and construction, painting and walls, garden and landscaping, roofing and exterior, home renovation and cost, measurements and conversions, plumbing and water, electrical and energy, and doors, windows and interior. Read more on the about page.