Wallpaper Roll and Pattern Repeat Calculator
Estimate full-height wallpaper drops and rolls with trim and straight pattern matching.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Count full-width vertical drops separately for every wall. Add top and bottom trim, round each drop length to a whole straight-match repeat, then fit whole drops per roll.
Drop=ceil((height+2 trim)/repeat)×repeat; rolls=ceil(total full-width drops/drops per roll)+spares
Worked example
Widths 4,3,4,3 m need 28 drops at 0.53 m width. Height 2.5 m plus 0.1 m trim rounds to 2.88 m with a 0.32 m repeat. Three drops fit in a 10 m roll: 10 rolls plus 1 spare.
Assumptions and input details
All walls use the same height; doors and windows are covered in full in this conservative estimate. Offcuts are not reused across walls. Straight-match patterns only, not half-drop, random-match optimization or horizontal hanging. Enter initial pattern-alignment waste if needed. Check actual roll labels and pattern instructions; no retail availability or batch color matching is inferred.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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