Wallpaper Calculator: Square Feet & Rolls

Estimate wallpaper rolls for one rectangular wall using full-height vertical strips. Enter the wall dimensions and the actual width and length of one roll. Add a total trimming allowance and, if applicable, a straight pattern repeat.

Calculate wallpaper for one wall

Use actual product dimensions, not a generic single- or double-roll label. This version supports no repeat or a conservative straight-repeat estimate. It does not support half-drop or other offset matches. Do not combine several walls into one width.

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Measurement systemUS: feet and inchesMetric: meters and centimeters

Wall width (feet)Wall height (feet)Roll width (inches)Roll length (feet)Total trim per strip, top + bottom (inches)

Trim is optional; blank means zero. Enter the combined top and bottom allowance, not an allowance for each end.

Pattern matchNo repeat / free matchStraight repeat (conservative estimate)Straight pattern repeat (inches)

For straight repeat, strip length including trim is rounded up to a whole repeat. Confirm cutting and starting-position allowances with the supplier. Do not use this option for a half-drop match.

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How to calculate wallpaper rolls

1. Divide wall width by roll width in matching units, rounding up to whole strips.
2. Add the combined top and bottom trim to the wall height.
3. For a straight repeat, round that cut length up to a whole pattern repeat.
4. Divide roll length by cut length and round down to full strips per roll.
5. Divide required strips by strips per roll and round up to whole rolls.

For measurement steps and cutting examples, read our guide to calculating wallpaper rolls.

Worked example without pattern repeat

A wall 12 feet wide and 8 feet high uses 24-inch-wide rolls that are 30 feet long. With 4 inches of total trim per strip, each strip is 100 inches long. The wall needs 144 / 24 = 6 strips. A 360-inch roll gives 3 full strips, so the estimate is 2 rolls. Wall area is 96 square feet, but roll purchasing depends on usable full-height strips, not area alone.

Straight-repeat example

For the same wall and 4-inch trim, a 24-inch straight repeat rounds the 100-inch cut length up to 120 inches. A 360-inch roll still supplies 3 strips, giving 2 rolls. Other roll lengths or repeat sizes can change how many strips fit. This is a simplified conservative repeat model, not an optimized cutting plan.

Why square footage alone is not enough

Dividing wall area by gross roll area can understate purchasing needs. Roll width determines the strip count, and height, trimming, and pattern repeat determine how many complete strips can be cut. Doors and windows may leave usable short sections, but this version does not optimize those offcuts or subtract openings.

Frequently asked questions

Does this support half-drop or offset matches?

No. Those products require a different cutting and matching plan. Ask the supplier for a product-specific quantity; do not use the straight-repeat option as a substitute.

Should I enter a single roll or double roll?

Enter the actual usable dimensions of one physical roll or continuous unit you will purchase. Packaging labels vary. If a package contains separate rolls, calculate using each physical roll's dimensions and confirm package quantities with the retailer.

Can I calculate multiple walls together?

This version handles one wall at a time. Adding all wall widths can undercount strips needed at individual walls. Separate calculations and summed whole-roll estimates may overestimate purchases because leftover full strips could be shared. Ask the supplier for a combined cutting plan.

Do I need extra for trimming?

Use the product or installer's recommended top and bottom allowances and enter their combined length. No automatic trim or spare-roll allowance is added. Product matching can require extra starting-position allowance beyond this simplified model.

What happens when I switch units?

All dimensions, trim, and repeat clear so numbers entered in feet are not reused as meters. Enter values again in the displayed units.

What inputs are supported?

Positive wall dimensions up to 1,000 feet or meters, positive roll width up to 10,000 inches or centimeters, and roll length up to 10,000 feet or meters. Optional total trim is 0 to 1,000 inches or centimeters. Straight repeat must be positive and no more than 10,000 inches or centimeters. Up to four decimal places are accepted, with a decimal point or comma and no thousands separators.

Related measurement tools

For rectangular areas only, see our Square Footage Calculator. For a different wall finish, try the Paint Calculator.

HandyMetric provides general estimation aids, not an installation or optimized cutting service. Verify product dimensions, matching instructions, and purchasing quantities with your supplier or installer.