FIELD GUIDE / PRINT GEOMETRY
The page is part of the system.
A4 and US Letter are close in size, but not interchangeable. Geometry changes the writing surface before the first rule is drawn.
01 / Two paper standards
A4 measures 210×297 mm. US Letter measures 8.5×11 inches, exactly 215.9×279.4 mm using 25.4 mm per inch. A4’s height-to-width ratio is approximately 1.414; Letter’s is approximately 1.294. Letter is wider and shorter in portrait.
02 / Rotate, don’t stretch
Landscape swaps width and height. Scaling a portrait design non-uniformly changes the grid-cell proportions and type shapes. Instead, recompute the usable rectangle, then lay out the seven columns within it.
03 / Margins and writing area
For uniform margin m, usable width is W − 2m and usable height is H − 2m. A4 with 12 mm margins leaves 186×273 mm before titles or headers. Subtract the title band and weekday header before dividing the remaining height into five or six rows.
04 / From diagram to printer
This visualizer shows proportions and dimensions, not a print-ready PDF. Check the printer’s non-printable edges, choose the intended paper size and inspect scaling settings. “Fit to page” may shrink a nominally exact layout. Zero margins in the diagram do not imply borderless printer support.