Wall Area With Openings
Subtract user-measured door and window openings from gross wall area for material planning.
Use this before paint, panel, or sheet estimates when openings materially reduce the surface to cover.
Open Wall Area With OpeningsThe decision guide / 11 calculators
Materials & quantities
Estimate common material quantities before you price a project.
Worksheet / 01 / 5 tools
Measure surfaces and coverings.
Subtract openings where needed, then plan paint, flooring, tile, or sheet quantities from the area that will actually be covered.
Paint Quantity
Estimate paint containers from wall area, coats, and stated coverage.
Use this as a planning estimate and confirm coverage on the product label.
Open Paint QuantityFlooring Quantity
Add an explicit waste allowance to a measured floor area.
Use this before comparing pack sizes, then follow the flooring manufacturer's allowance guidance.
Open Flooring QuantityTile Quantity
Estimate whole tiles from floor area, tile dimensions, and an explicit cutting allowance.
Use this for a purchase count after measuring the install area; keep tile dimensions in centimetres and check pack sizes separately.
Open Tile QuantityDrywall Sheets
Estimate whole sheets from wall area, sheet coverage, and a user-supplied waste allowance.
Use this for an early order count after measuring walls; enter the actual sheet coverage rather than assuming a product size.
Open Drywall SheetsWorksheet / 02 / 3 tools
Plan concrete and loose volume.
Convert consistent dimensions into volume, then use the selected product yield or supplier unit rather than assuming a universal bag or load size.
Concrete Slab Volume
Calculate slab volume from length, width, and depth in consistent units.
Use this for an early volume check and confirm structural design, reinforcement, and ordering with a qualified professional.
Open Concrete Slab VolumeConcrete Bag Count
Round a measured concrete volume up to whole bags using the yield printed for your product.
Use this for an order estimate only after entering the actual per-bag yield from the product label.
Open Concrete Bag CountMaterial Volume
Calculate loose material volume from an area and user-supplied depth for gravel, mulch, or similar material.
Use this shared volume calculation for gravel or mulch when the geometry is the same, then convert cubic metres to the supplier's order unit.
Open Material VolumeWorksheet / 03 / 2 tools
Allow for lumber and fencing.
Keep board dimensions, fence spacing, gates, and corners explicit so a quantity estimate can be checked against the intended layout.
Board Feet
Calculate nominal board feet from thickness, width, and length in common lumber units.
Use this to compare a measured lumber quantity with a supplier's board-foot pricing, while retaining actual piece counts separately.
Open Board FeetFence Post Planning
Estimate fence posts from run length, post spacing, corners, and gate post assumptions.
Use this as a named-assumption planning count; define gate and corner treatment before ordering the rest of the fence materials.
Open Fence Post PlanningWorksheet / 04 / 1 tools
Add an energy-planning estimate.
Use device power, operating time, and your own tariff to make an energy-cost scenario visible; this is separate from material quantity planning and not a utility bill forecast.
Electricity Cost
Estimate energy cost from device power, operating time, and the user's electricity price.
Use this for a device-level estimate with your own tariff and schedule; it is not a utility bill forecast.
Open Electricity CostFrom calculation to decision
Choose the right lens.
Read the result alongside its definition, not as a standalone score.
How we document formulas and limitationsStarting a material estimate?
Measure the actual surface first, subtract openings where appropriate, and name the coverage or waste assumption. A calculator cannot see the room, slope, pattern, or product label.
Ordering concrete or loose material?
Use consistent dimensions for volume, then convert with the chosen product's yield or supplier unit. Keep density, settling, delivery minimums, and structural requirements outside the arithmetic.
Comparing a project with its running cost?
Electricity cost is an energy-use scenario, not a material quantity. Enter your own tariff and schedule and compare the estimate with the bill's tariff scope.