Don't Buy Short: The "Strip Method" Wallpaper Estimator
Buying wallpaper is not like buying paint. With paint, you just calculate total square footage. With wallpaper, you must calculate Strips. If you use a simple square-footage calculator, you will likely run out of paper because it doesn't account for the waste created when cutting around the pattern. Our Advanced Wallpaper Calculator uses the professional "Strip Method" to ensure you have enough full-length sheets to cover your walls from ceiling to floor, matching the pattern perfectly every time.
Why Square Footage Calculators Fail
Imagine a wall that is 8 feet high. If your wallpaper roll is 33 feet long, you can get exactly 4 full strips (32 feet) out of it, with 1 foot of waste.
However, a basic calculator sees that leftover 1 foot as "usable area" and tells you to buy less paper. In reality, you cannot paste a 1-foot scrap in the middle of your wall. Our tool calculates how many usable drops you get per roll.
The "Pattern Repeat" Nightmare
Unless you are buying a solid color, your wallpaper likely has a repeating design (e.g., a flower that appears every 18 inches). To line up the flowers from one strip to the next, you often have to cut off and throw away inches of paper at the top of every sheet. This is called the Pattern Repeat.
- Random Match (0"): No waste. You can line up strips anywhere. (e.g., Vertical stripes, grasscloth).
- Straight Match: The pattern matches horizontally. Minimal waste.
- Drop Match (Half-Drop): The hardest to estimate. The pattern runs diagonally. You often lose up to half the repeat length on every strip.
US Double Rolls vs. Euro Rolls
The wallpaper industry uses confusing terminology for packaging.
US Standard: Most papers in the US are sold as "Double Rolls" (essentially two single rolls wrapped together). A standard US Double Roll is 20.5 inches wide and 33 feet long (approx 56 sq ft).
European Standard: Euro rolls are narrower (21 inches or 53cm) and shorter (33 feet or 10m). Always check the label before buying!
Frequently Asked Questions
Should I subtract windows and doors?
Professional installers suggest you ignore standard-sized windows and doors when calculating. Treat the wall as solid. This provides you with a built-in safety buffer for mistakes. Only subtract large openings (like double French doors) using the "Deductions" field in our tool.
What is a "Batch Number"?
Wallpaper is printed in batches. Always buy all your rolls at the same time and ensure they have the same Lot/Batch Number. Rolls from different batches may have slight color variations that will be visible on your wall.
How much overage should I buy?
We recommend buying one extra roll beyond what the calculator predicts. If you damage a strip during installation or need to patch a tear years later, having a matching roll in the closet is a lifesaver.