Flooring Calculator

How much flooring do I need?

Measure the room and any closets or connected sections, add a waste allowance, then divide by the exact coverage printed on one box. Flooring is purchased in whole boxes, so the calculator rounds the box count up. Choose room dimensions plus extra area, or enter total measured square feet directly. In total-area mode, the room dimensions and extra-area inputs are excluded.

boxes = round up((room area + extra area) x (1 + waste %) / box coverage)

Flooring example

A 20 ft by 12 ft room contains 240 square feet. With 10% waste, the target is 264 square feet. If each box covers 24 square feet, the order is exactly 11 boxes. At $48 per box, estimated flooring cost is $528 before tax and delivery.

Coverage ordered and leftover material

Because boxes are rounded up, purchased coverage can exceed the waste-adjusted target. For example, a 250 sq ft total with 10% allowance needs 275 sq ft; boxes covering 24 sq ft require 12 boxes, providing 288 sq ft. That is 25 sq ft of planned allowance plus 13 sq ft of box-rounding excess, or 38 sq ft beyond measured area. It is not a guarantee of 38 sq ft of reusable spare planks: cutting losses and offcut shapes matter.

Underlayment

Open Underlayment options to include or exclude separate rolls. When included, roll count is based on measured floor area plus its own entered roll allowance, not on purchased flooring coverage. Flooring waste and roll allowance are independent. In the 240 sq ft example, zero roll allowance and 100 sq ft per roll require 3 rolls; at $35 each, underlayment is $105 and the combined materials estimate is $633.

Some flooring includes an attached pad, some systems require a specific moisture or sound-control product, and some installations use no separate underlayment. Follow the exact flooring and underlayment instructions, including any overlap requirement. Lowe's project planner describes using carton-specific square-foot coverage and separately dividing required area by underlayment package coverage. No product's compatibility or installation method is determined here.

Cost and measurement assumptions

Enter the actual price per box and, when included, per roll. A blank price means unknown, not free; the complete total appears only when all included prices are entered. An explicit $0 remains a zero-price scenario. The estimate excludes installation labor, preparation, trim, adhesive, tax, delivery, minimum orders and returns. The chart shows square-foot coverage only, without mixing dollars on the same scale. Dimensions and coverage must be positive; allowances range from 0% to 100%, with at most one billion packages per included material.

For irregular rooms, use the area calculator or square footage calculator to measure non-overlapping sections, then enter their sum in Total square feet mode. Vinyl and laminate orders depend on the selected product's carton coverage, layout and instructions; the default is an editable example, not a product recommendation.

Waste allowance

Room shape, installation direction, plank length, pattern matching, defects, and future repair stock affect waste. Use the allowance specified by your installer or product guidance instead of treating a default percentage as universal.

For a measured walkthrough of L-shaped and other irregular rooms, including a worked square-footage example and ordering checks, read how to calculate square footage for an irregular room.

Frequently asked questions

Should I use price per box or price per square foot?

This calculator uses price per box so the cost matches the rounded number of packages purchased.

Can I combine multiple rooms?

Yes. Add non-overlapping measured room and closet areas and enter their sum in Total square feet mode. Do not also add one room's dimensions again. Estimate separately when products, layouts or allowances differ.