Flooring Calculator
Enter the room's length and width, the coverage printed on the box and a waste allowance to get the boxes to buy and what is left over, rounded up once. Each maker's allowance is in the table.
Estimates for planning, not professional advice. Read the full notice.
The drawing did not open. Length and width are still here.
Room: shape and size
Skip the drawingDrag a round corner to move it. The small hollow diamond on a side is its curve handle: drag it across the side to curve the side (it is not a corner). To add a corner (a new point), tap the side itself, then choose Add a point here. Tapping a corner or a side opens its actions. Drag empty space to move the view; pinch, or Ctrl and the mouse wheel, to zoom. The keys are listed under Keys.
Keys
- Tab
- next corner; each says how far it is from corner 1
- Arrow keys on a corner
- move it one square; ten with Shift; 1/16 in with Alt
- Delete or Backspace
- remove the corner; its two sides join in one straight side
- + on a corner
- add a corner halfway along the next side
- Arrow keys on the drawing
- move the view; farther with Shift
- + and - on the drawing
- zoom in and out
- 0 on the drawing
- show the whole shape
- Ctrl+Z (Cmd+Z on a Mac)
- undo, except inside a typed field (it keeps its own)
- Ctrl+Shift+Z or Ctrl+Y
- redo
- Escape while dragging
- put it back where it was
- Enter on a corner or side
- go to its actions
- Escape in the actions
- close them and go back to the drawing
The drawing did not load. Check your connection and try again.
- Area
- 168 ft²
- Perimeter
- 52 ft
- Cut-out edges
No area until the shape is fixed.
Estimate for planning, from what you entered and the product data shown. Check product labels and your supplier before you buy.
Shape: Rectangle Change
Sides
Corners
Cut-outs
Feet and inches, like 12' 6"
Example: a bedroom floor
8 flooring, by the box
- Floor area 168 ft²
- Area with the waste allowance, before rounding 184.8 ft²
- Flooring bought 187.2 ft²
- Bought beyond the floor's own area 19.2 ft²
Your project
Enter a size to see your total.
Each product is rounded up once for the whole project, so the total can be less than the items bought alone added together. A line counted from a cut layout (sheets, boards or tiles laid out piece by piece) is counted for each item and added.
Shopping list
| Item | Size | Buy |
|---|---|---|
| Flooring, by the box | flooring, by the box | 8 |
Save on this device
Saved projects
No saved projects yet.
Worked example: a bedroom floor
Show the working
- Area: length times width 14 ft × 12 ft = 168 ft²
- Add the waste allowance, once 168 ft² × 1.1 = 184.8 ft²
- Divide by the coverage of one box 184.8 ft² ÷ 23.4 ft² = 7.9 boxes
- Round up once, to whole boxes 7.9 boxes = 8 boxes of flooring
Assumptions
The figures behind the example. Sourced figures link to their source below; a default is a starting value to check against your label or supplier.
| Assumption | Value | Details and changes |
|---|---|---|
| Waste allowance | 10% | |
| Default Our starting value, not a sourced figure; your own allowance, added once. Change it for your layout. The allowances the makers print are in this page's table. | ||
| Coverage of one box | No default | |
| Default From the box label. Check your label or supplier. | ||
| Plank size | No default | |
| Default Width and length from the label; it does not change the count, which follows the box coverage. Check your label or supplier. | ||
| Expansion gap | No default | |
| Default Shown for your own layout; it does not change the box count. Check your label or supplier. | ||
Feet and inches, like 12' 6"
Boxes for common room sizes
Boxes for common room sizes at an example box coverage, with the waste allowance added once
| Room | Floor area | Boxes at 20 ft² a box (example) |
|---|---|---|
| 10 × 10 ft | 100 ft² | 6 |
| 10 × 12 ft | 120 ft² | 7 |
| 12 × 12 ft | 144 ft² | 8 |
| 12 × 14 ft | 168 ft² | 10 |
| 12 × 16 ft | 192 ft² | 11 |
| 14 × 16 ft | 224 ft² | 13 |
| 16 × 20 ft | 320 ft² | 18 |
The box coverage is an example, not a product's. Your own label gives the real coverage, so enter it in the field above for your count.
Waste allowances the makers print
The cutting allowance each maker's installation sheet adds to the square footage, by sheet and layout
| Maker's sheet and layout | Allowance printed |
|---|---|
| AHF Products, waterproof locking hardwood, straight layout | 5% (per AHF Products' published data, checked Nov 12, 2026) |
| AHF Products, waterproof locking hardwood, diagonal layout | 10% (per AHF Products' published data, checked Nov 12, 2026) |
| AHF Products, rigid-core locking floors | 10% (per AHF Products' published data, checked Nov 12, 2026) |
| Shaw Industries, engineered hardwood, cutting allowance | 5% (per Shaw Industries' published data, checked Nov 12, 2026) |
Product names are trademarks of their owners. HoneyDoMath is not affiliated with, sponsored by or endorsed by these makers. Figures come from each maker's published sheets and are shown for information only.
The makers' figures differ by product and by layout. The sheet for the floor you buy sets the allowance; change the waste field above to match it. One sheet says diagonal, herringbone or bordered layouts need a higher percentage and prints no number.
Questions
How much extra flooring should I buy?
The waste allowance starts at a typical figure and you can change it. The makers print different figures for different floors and layouts, so the table lists them beside the field. The calculator adds the allowance once to the floor area and rounds up once to whole boxes.
How many boxes of flooring do I need for a 12 × 12 room?
The table of common room sizes shows the boxes for a 12 × 12 ft room and others at an example box coverage. Box coverage differs by product, so enter the coverage from your own label for your count.
Does the expansion gap change the number of boxes?
No. The gap is shown as your own input for your layout and is not taken off the floor area, so the count follows the room's full area.
Why does the calculator show square feet bought?
A box holds a fixed coverage, so you buy whole boxes. The square feet bought and the amount beyond the floor's own area show what the last box and the waste allowance add.
Sources (3)
-
Waterproof Locking Hardwood with Angle/Angle Technology Installation Instructions (opens in new tab), AHF Products, installation sheet WF-1256-525.
Manufacturer data.
“When flooring is ordered, 5% must be added to the actual square footage needed for cutting and grading allowance (10% for diagonal installations).”
Per AHF Products' published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 1) -
Rigid Core Locking Installation System (opens in new tab), AHF Products, installation sheet, undated.
Manufacturer data.
“Most installations will need approximately a 10% cutting allowance added to the square footage of the room.”
Per AHF Products' published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 2) -
Engineered Hardwood Flooring Installation Guidelines (Herringbone) (opens in new tab), Shaw Industries Group, installation sheet, footer 060719.
Manufacturer data.
“5% cutting allowance, depending on layout, must be added to the actual square footage amount needed. (Diagonal, herringbone, or bordered installations will require a higher percentage)”
Per Shaw Industries' published data, checked Nov 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 3)
These are summaries of what the sources say, not professional advice. Codes and product data change. Check with your building department and the product label about your own project.
Sources
- [1] AHF Products, Waterproof Locking Hardwood with Angle/Angle Technology Installation Instructions. Checked November 12, 2026. https://www.bruce.com/cdn/content/sites/2/WF-1256-525_8.5x11_Waterproof-HW_Install_ENG.pdf
- [2] AHF Products, Rigid Core Locking Installation System. Checked November 12, 2026. https://www.bruce.com/cdn/content/sites/2/AHF-RigidCore-Installation.pdf
- [3] Shaw Industries, Engineered Hardwood Flooring Installation Guidelines (Herringbone). Checked November 12, 2026. https://qmsview.shawinc.com/QMS_View/files/93/939bd3b8-8775-485f-8dfe-ca5b54bbbf75.Pdf