Flooring Calculator
Estimate flooring for multiple rooms with chosen waste, whole packs and optional cost.
This tool runs entirely in your browser. Your data is never uploaded, never stored, and never leaves your device.
Combine measured rooms using one flooring product to estimate whole boxes, separate rounding surplus and an optional material-only cost.
How to use it
- 1Enter non-overlapping room rectangles and actual floor areas to exclude.
- 2Choose your allowance, the carton's coverage and optional price per box.
- 3Calculate the pooled whole-box order and inspect the area breakdown.
- 4Download a JSON estimate; any edit clears stale results.
Example
- Input
- 17 m² net, 10% allowance, 2.2 m²/box, USD 45.50/box.
- Output
- 9 boxes; 19.8 m² purchased; 1.1 m² rounding surplus; USD 409.50 material subtotal.
Example price and allowance, not a market quote or installation specification.
What happens to your data
Measurements and prices are calculated locally and are not uploaded or saved. The optional JSON file records your active inputs and assumptions.
Last updated October 2026
A flooring order is not simply the room's area divided by a guessed plank size. Carton coverage varies by product, offcuts change the requirement, and rounding every room separately can leave unnecessary unopened boxes. This flooring calculator combines up to twenty rectangular floor areas using one product, subtracts measured areas that will not be covered, applies your chosen allowance and rounds the pooled requirement to whole boxes.
It keeps net floor area, allowance, purchased carton coverage and surplus separate. You can also enter a price per box for a materials-only subtotal. This is useful when comparing boxed laminate, vinyl plank or wood products with different carton sizes; it is not a carpet-roll layout, plank cutting optimizer or installation specification.
How it works
For each room, calculate length × width − excluded floor area. Add those non-overlapping net areas, multiply by 1 + allowance/100, divide by the coverage printed on the actual carton and round up once. The output multiplies whole boxes back by their coverage, then subtracts required coverage to show extra area caused only by box rounding. It does not hide that extra area inside the waste percentage.
Use separate rectangles for an L-shaped room, an alcove or a connected hallway. Do not count an overlap twice. Excluded area is physical floor that will not receive flooring; the vertical area of a door or window is not a deduction from floor area. The calculator can reject a deduction larger than its rectangle, but cannot inspect your floor plan, cabinet installation rules or measurements.
A product's carton coverage, selected installation pattern and manufacturer's waste guidance matter more than a universal percentage. The allowance begins at zero and the worked example uses 10% only to demonstrate arithmetic. Read the current installation instructions for your actual product, particularly for patterned layouts, stairs, expansion clearances and unsuitable substrates. Whole cartons are pooled only when all rooms use the same compatible product.
Optional price is per whole box, not per square metre or square foot. Subtotal equals boxes × price per box. It omits delivery, taxes, labour, adhesive, trims and underlay, and the currency selector is a label rather than an exchange-rate service. Decimal measurements and box boundaries use exact fractions before display rounding; price accepts up to two decimal places. The JSON download preserves active room inputs, exclusions, product settings and assumptions.
Worked example: Two rooms and one shared carton order
- Input
- 4 × 3 m less 1 m², plus 2 × 3 m; 10% allowance; 2.2 m²/box; USD 45.50/box.
- Result
- 17 m² net; 18.7 m² required; 9 boxes covering 19.8 m²; 1.1 m² pack surplus; USD 409.50 material subtotal.
Example price and allowance are hypothetical inputs, not market prices or installation recommendations.
Common use cases
- Combine a bedroom, hallway and alcove using the same boxed flooring before rounding cartons.
- Compare two products by actual carton coverage and box price rather than misleading shelf-price comparisons.
- Separate your chosen cutting allowance from the extra coverage created by a whole-box order.
- Save a room-by-room JSON takeoff for a supplier discussion without uploading a floor plan.
Frequently asked questions
How many boxes of flooring do I need?＋
Divide the combined floor area with your allowance by the coverage per box, then round up. For 17 m² net area, 10% allowance and 2.2 m²/box, the requirement is 18.7 m² and the order is 9 boxes. Those boxes cover 19.8 m², leaving 1.1 m² above the stated requirement.
Should I add 10% waste to every job?＋
Not automatically. Product and layout guidance differ. Choose an allowance from your manufacturer's instructions and actual cutting plan; the calculator starts at zero and adds no hidden percentage. The example's percentage is not a recommendation for your room.
What counts as an excluded area?＋
Only floor area you genuinely will not cover, measured in m² or ft². Do not subtract doors and windows measured on walls. Confirm whether your selected product goes beneath particular fixtures before excluding their footprints.
Can rooms use different flooring products?＋
Calculate those products separately. This tool pools one coverage-per-box value, price and allowance across all entered rooms. It cannot share cartons across different colours, formats, products or installation requirements.
Does it calculate plank cuts, underlay or carpet?＋
No. It is a boxed-product area estimate, not a cut/reuse plan. Underlay, trims, steps and adhesive are separate purchases. Carpet sold from a fixed-width roll needs a roll-layout calculation, not this carton formula.
Are estimates saved or uploaded?＋
No input is uploaded or stored by the calculator. The optional JSON file is downloaded to your device. Every input edit, row addition/removal or unit change clears the previous output and download until you calculate again.
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