Wallpaper calculators.

Wallpaper is bought in rolls, bolts or yards and hung in drops, and the way it is sold decides which of these five calculators fits. None of them divides the wall’s area by a roll’s coverage: each cuts the drops the wall needs and then fits those cuts onto what you would order.

Match the listing to a calculator

• The listing gives you: A roll width, a roll length and a pattern repeatWallpaper calculator

  Cuts every drop to whole repeats, shortens only the drops a door or window clears, and places each cut on a numbered roll.

• The listing gives you: A match type: straight, half-drop, third, quarter or randomWallpaper calculator with repeat

  Shows, drop by drop on one wall, the paper each kind of match loses to the pattern.

• The listing gives you: A price per linear yard, in goods 36, 45 or 54 inches wideWallpaper calculator in yards

  Sums the yards from the drops themselves, hung vertically or railroaded, against the area-divided-by-width figure.

• The listing gives you: York WallcoveringsYork wallpaper calculator

  Re-cuts York’s room chart in drops on the bolt or on the product roll, and compares three ways of treating openings.

• The listing gives you: Painted PaperPainted Paper wallpaper calculator

  Plans the drops on either roll length the brand sells, with the vendor’s own estimate and the list price beside the plan.

Two brand pages, and why only two

A brand page exists here only where the brand’s real roll sizes and its own estimating method were read and dated. That is the case for York and Painted Paper; Calculiva is independent of both. For paper from anyone else, take the roll width, roll length and repeat from the label and enter them in the general calculator; the arithmetic is the same and nothing is assumed about the product.

Repeat or yards?

The two are not alternatives. The repeat decides how long each drop must be cut; yards are only the unit the seller bills in. A patterned wallcovering sold by the yard needs the yardage page, while the match page is the place to see what a half-drop costs before choosing a design. Roll and bolt sizes quoted on the brand pages are dated in the source register.