Flooring Calculator

Enter the room dimensions and the coverage printed on the box, add a waste allowance, and get the square footage, the number of boxes and an optional cost.

Works for laminate, luxury vinyl plank, engineered wood and solid hardwood — anything sold by the box.

How to use the flooring calculator

Enter the room dimensions.

Add the box coverage and waste allowance.

Read square footage, boxes and cost.

Why use the Build Tally flooring calculator

Rounds to whole boxes

Because that is how flooring is actually sold.

Your box, your coverage

Enter the figure from the product you chose.

Underlay included

Area for underlay calculated alongside.

Add-a-room

Total several rooms in one calculation.

Why box coverage is the number that matters

Flooring is priced per square foot but sold by the box, and box coverage varies a lot between products — anywhere from about 15 to over 30 square feet. Two products at the same price per square foot can need very different box counts for the same room, and you always round up to a whole box. That is why this calculator asks for the coverage from the box you are actually buying rather than assuming a standard.

Waste, direction and the first and last row

Ten percent is the usual allowance for a straight layout in a simple room, rising to 15% for diagonal installations and rooms with lots of doorways, jogs and closets. Beyond the percentage, check the first and last row: if the room width divides so that the final plank is a narrow sliver, rip the first row narrower so both edges are a sensible width. Planks are normally run parallel to the longest wall or towards the main light source, which also affects how many cuts you make.

Underlay, transitions and acclimation

Most floating floors need underlay unless it is pre-attached, and a moisture barrier over concrete regardless. Budget for transition strips at every doorway and a change of level, and for beading or quarter-round around the perimeter, since floating floors need an expansion gap at every wall. Let the boxes acclimate flat in the room for 48 hours before fitting — laid straight off a cold truck, planks expand afterwards and the floor buckles.

Read the guide: How to Calculate Square Footage of a Room, a House or a Yard

Frequently asked questions

How many boxes of flooring do I need?

Divide the room area plus waste by the coverage printed on the box, then round up. Enter both above and the calculator does it.

How much flooring waste should I allow?

Ten percent for a straight layout, fifteen for diagonal patterns or rooms with many cuts and doorways.

How much does a box of laminate cover?

Typically 15–30 square feet, but it varies by product — use the figure on the box you are buying.

Do I need underlay?

Usually yes, unless the planks have it pre-attached. Over concrete you also need a moisture barrier.

Should I buy an extra box?

One spare box is worth having. Batch shading varies and a damaged plank years later is much easier to replace from stock.

Which direction should planks run?

Usually parallel to the longest wall or towards the main window. It is a visual choice, but it changes how many cuts you make.