154 sq ft
Flooring Calculator
Enter a room's length, width, and door/window openings once and get flooring boxes (with waste), tile count for wet areas, and baseboard/casing footage together.
Material ListFloor area Boxes to buy Tiles Grout Thinset bags Baseboard to buy Door casing to buy Window casing to buy
“How much flooring do I need” starts with square footage, but the real order quantity depends on material, layout pattern, and waste percent — and most flooring jobs also touch tile in a wet area and new baseboard around the room. This page runs Room Layout once for floor area and perimeter, then feeds that into Flooring, Tile, and Trim. Each calculator below is the same one available on its own page — nothing here is a new formula.
Flooring material estimating: sq ft and waste %
Flooring waste percent depends on both material and layout pattern: a straight-run install wastes the least, while diagonal and herringbone patterns cut more material at the perimeter and need a higher waste allowance. This calculator locks in a waste percent per material/pattern combination (hardwood, engineered, LVP, or laminate, each with straight/diagonal/herringbone options) and applies it to the room’s floor area before rounding up to whole boxes.
Floor area comes from Room Layout’s length x width, so changing the room dimensions updates the flooring box count automatically without re-entering area by hand.
Room dimensions, doors, and windows
Enter room length, width, and doors/windows once. Flooring, tile, and trim each add a few fields of their own below (material, tile size, waste percent) that a room's dimensions alone don't determine.
Room Layout
Floor area and perimeter from room length and width — the shared backbone for Flooring, Tile, and Trim below.
This room has 367.99 sq ft of wall and 154 sq ft of floor.
This room has
Room Layout result
Detail values
- Perimeter
- 50 ft
- Wall area
- 367.99 sq ft
- Wall segments
- 14.00, 11.00, 14.00, 11.00 ft
Assumptions
Formula details
- Floor area: 0.5 x abs(sum(xi x yi+1 - xi+1 x yi))
Flooring
Boxes to buy from the room's floor area, material, layout pattern, and box coverage.
You'll need 9 boxes of flooring, plus waste, for 154 sq ft.
You'll need
Flooring result
9 boxes
Detail values
- Waste factor
- 7%
- Adjusted area
- 164.78 sq ft
Assumptions
- Waste factor: 7% (editable, default 7%)
Formula details
- Adjusted area: area × (1 + waste%)
Tile
Tile count, grout weight, and thinset bags over the same room floor area, for a wet-area tile floor.
You'll need 170 tiles and 9.87 lb of grout for 154 sq ft.
You'll need
Tile result
170 tiles
10 lb
7 bags
Detail values
- Tiles needed
- 170
- Grout fraction of module
- 2.05%
- Thinset weight
- 324.84 lb
Assumptions
- Grout type: Unsanded (100 lb/cu ft, editable)
- Trowel notch: 1/4" x 1/4" square notch (~0.1875in bed, editable)
- Thinset bag weight: 50 lb (editable)
- Waste: 10% (editable)
Formula details
- Grout coverage ratio: (tile L × tile W) / ((tile L + gap) × (tile W + gap))
Tile-to-module area ratio; the remainder of each module is grout.
- Thinset weight: area × trowel bed thickness × thinset density
Trim
Baseboard, door casing, and window casing footage from the room's perimeter and openings.
You'll need 86 ft of trim for this room.
You'll need
Trim result
52 ft
18 ft
16 ft
Detail values
- Baseboard linear feet
- 47 ft
- Door casing linear feet
- 16.34 ft
- Window casing linear feet
- 14 ft
Assumptions
- Trim context: Interior (MDF, finger-joint, or wood baseboard & casing)
- Waste: 10% (editable)
Tile for wet areas
Tile is run over the same room footprint as Flooring here, which fits a bathroom, laundry, or mudroom floor being tiled instead of covered with sheet flooring. Tile count factors your tile size and waste percent; grout weight and thinset bag count come from joint width, joint depth, and a density constant you can adjust for your grout product.
If only part of the room is tiled (a shower alcove, for example) rather than the full floor, switch Tile to manual entry and enter that smaller area directly.
Trim and baseboard footage
Baseboard runs the room’s perimeter minus door widths (a door interrupts the baseboard run at floor level), while door and window casing is a separate linear-footage total based on each opening’s width and height. This page tracks doors and windows as two separate lists so Trim can subtract door widths from the baseboard run while still casing both doors and windows.
Perimeter comes from Room Layout, so a longer or shorter room updates the baseboard total the same way it updates flooring and tile above.
FAQ
Why does Tile run over the full room floor area?
This page assumes Tile covers the same footprint as Flooring, which fits a fully tiled wet-area floor. If only part of the room is tiled, switch Tile to "Manual entry" and enter that smaller area directly.
Why are doors and windows tracked separately instead of one combined opening list?
Trim needs door widths subtracted from the baseboard run (a door interrupts the floor-level baseboard) while both doors and windows get their own casing footage. Room Layout combines both lists into one openings set for its own wall-area math.
How is flooring waste percent determined?
Waste percent is a locked reference table by material and layout pattern (hardwood, engineered, LVP, or laminate, each with straight, diagonal, or herringbone options) -- it isn't user-editable on this page since it reflects typical cut loss for that combination.
Can I fine-tune just one calculator without changing the room dimensions?
Yes. Flip any section to "Manual entry" to edit its inputs directly without changing the room layout or the other calculators.
Disclaimer
Material estimate and general reference only. Verify manufacturer waste recommendations, grout/thinset coverage, and field conditions before ordering or starting work.