Carpet Calculator

How to Calculate How Much Carpet You Need

Broadloom carpeting cannot simply be measured as raw floor square footage. Unlike modular hardwood planks, laminate, or vinyl tiles sold in small cartons, wall-to-wall carpeting is manufactured and shipped in large continuous rolls in widths that vary by product, supplier, and market. The widths below are layout examples only; confirm the selected product's actual roll width and availability before ordering.

Carpet is ordered by linear length cut off the master roll. For example, a 10-ft wide room covered with a 12-ft roll leaves a 2-ft offcut strip along its entire length. A room wider than the roll requires multiple strips joined by seams. Confirm the exact manufactured roll width, available inventory, and seam layout with your supplier or installer. This calculator compares rectangular layouts; it does not create a measured seam or cut plan.

Room Orientation & Roll Run Direction

The direction you unroll broadloom carpet across a room materially affects the linear footage needed and the number of seams created:

• Run along length: Carpet strips run parallel to the room's length dimension. The room width is spanned by roll widths.
• Run along width: Carpet strips run parallel to the room's width dimension. The room length is spanned by roll widths.
• Auto (lower material): Compares both simple rectangular orientations and selects the layout requiring less linear roll length.

Important: The Auto selection evaluates simple rectangular layouts only. In actual installations, carpet pile sweep direction, pattern alignment, doorway transitions, sight lines from primary entrances, and seam visibility often dictate a specific orientation even if it requires slightly more yardage.

Square Feet to Square Yards: North American Ordering Unit

In the United States and Canada, residential broadloom carpet has historically been priced and quoted in Square Yards:

For example, if a planning estimate is 270 square feet, its area equivalent is:270 ÷ 9 = 30 square yards.

12-Foot vs. 15-Foot Broadloom Rolls

The selected product's roll width affects how the room can be cut and where seams may fall. These examples do not describe every product or installation:

The Importance of Carpet Pile Direction (Nap Sweep)

When carpets are tufted, the yarn fibers naturally angle in one direction, known as the pile direction or nap.

Pile direction can change how adjoining pieces look under room lighting. Follow the selected carpet's installation instructions and have the installer confirm pile direction and seam placement before cutting.

Pattern Repeat and Material Allowance

There is no single allowance that fits every room or carpet. Room shape, pattern repeat, pile direction, seam location, and the installer's cut plan affect the amount to order. Choose an allowance only after checking the selected product and proposed layout:

• Pattern Matching Limitation: This calculator provides a geometric planning estimate and does not calculate horizontal or vertical pattern repeat offsets.
• Patterned Carpets: Pattern repeat and match type affect how strips align. Use the manufacturer's pattern details and installer cut plan; this calculator does not estimate repeat offsets or prescribe a percentage.

Worked example: a 10 ft × 14 ft room with a 12 ft roll

The floor is 140 sq ft. With strips running along the 14 ft dimension, one 12 ft-wide strip needs 14 linear ft of roll, covering 168 sq ft. The alternative direction needs two 10 ft strips, or 20 linear ft and 240 sq ft, so Auto selects the first layout.

An illustrative 10% allowance on the floor area gives 154 sq ft. The calculator uses the larger of that amount and the simple roll layout: 168.0 sq ft (18.67 sq yd). It does not add 10% again to the 168 sq ft roll area. This is a rectangular planning example; trimming, pattern alignment, usable offcuts and the final cut plan need the installer’s check.

Related Guides & Interior Calculators

Explore related guides and interior renovation planning tools:

• Carpet Roll Width & Room Layout Guide - Learn how roll widths and room dimensions interact during installation planning.
• Flooring Calculator - Calculate square footage and carton counts for hardwood, vinyl plank, and tile.
• Paint Calculator - Estimate paint gallons and coverage for walls, trim, and ceilings.