Open Paper Box Blank and Fold Calculator
Calculate a rectangular blank and fold positions for a zero-thickness open box made by removing four square corners.
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
Add twice the side height to each base dimension. Remove a square of that height from every blank corner and fold along the central base rectangle.
Blank width=base width+2height; blank length=base length+2height; removed area=4height²
Worked example
A 10×15 cm base with 4 cm sides uses an 18×23 cm blank with four 4×4 cm corner squares removed. Ideal box volume is 600 cm³.
Assumptions and input details
Ideal zero-thickness sheet and open top, without glue tabs, overlap, lid, thickness, scoring offsets or bend radii. The outline shows the full blank and central base; four corner squares are the removed regions. This is a geometric blank reference, not a ready-to-print production dieline or an assurance that a real board stock folds to those internal dimensions.
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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