Add each rectangle
Measure each room or section separately. Length × width gives the area for that space.
Tool Switcher: Flooring
Project toolsTools
Room by room
Flooring Calculator
Add rooms, halls, and closets, then estimate total coverage in square feet or square metres, installation waste, full cartons, and cost.
- Multiple rooms
- US and metric units
- Full-box rounding
Project calculator
Flooring Calculator
Add multiple rooms and estimate full boxes, overage, and cost.
Methodology
One order from multiple spaces
Combine the areas
Room totals are added before waste is applied, so the project is planned as one flooring order.
Add cutting allowance
Straight installation starts at 10%, matching major retailer guidance. Complex layouts can use the editable 15% preset.
Round to cartons
Required coverage is divided by the manufacturer-listed coverage per box and rounded up.
Worked example
A living room and hallway
192 ft²living room
+32 ft²hallway
=246.4 ft²with 10% waste
If each carton covers 20 ft², buy 13 cartons for 260 ft² of purchased coverage.
Frequently asked questions
A second look at the estimate.
Can I add several rooms?
Yes. Add each rectangular section and the calculator combines the area before applying waste.
How many boxes of flooring do I need?
Enter the manufacturer-listed coverage per carton. The calculator divides the adjusted project area by that coverage and rounds up to a whole box.
Can I calculate flooring in square metres (m²)?
Yes. Switch to Metric to enter room sizes in metres and package coverage in square metres. The same physical project remains unchanged when you switch units.
Does the result include underlayment?
No. Underlayment, trims, transitions, and moisture systems require separate product-specific planning.
Sources and limitations
This tool estimates material coverage only. Product instructions control acclimation, expansion gaps, acceptable subfloors, moisture limits, installation direction, and warranty requirements.
- Lowe’s flooring buying guide
- Lowe’s laminate installation guidance
- The Home Depot vinyl flooring guidance
Last reviewed: August 21, 2026