Quarter-inch ruled US Letter paper
Set line spacing to 6.35 mm, the exact metric value of one quarter inch. With a half-inch edge margin and one inch of extra top space, the first rule is 1.5 inches from the top and 37 writing lines fit through the half-inch bottom margin.
The ruled sheet
A complete SVG dimensioned in millimetres. Print at 100% or Actual size to keep the selected spacing.
Every horizontal rule
| 1 | 38.1 | 12.7 | 203.2 |
| 2 | 44.45 | 12.7 | 203.2 |
| 3 | 50.8 | 12.7 | 203.2 |
| 4 | 57.15 | 12.7 | 203.2 |
| 5 | 63.5 | 12.7 | 203.2 |
| 6 | 69.85 | 12.7 | 203.2 |
| 7 | 76.2 | 12.7 | 203.2 |
| 8 | 82.55 | 12.7 | 203.2 |
| 9 | 88.9 | 12.7 | 203.2 |
| 10 | 95.25 | 12.7 | 203.2 |
| 11 | 101.6 | 12.7 | 203.2 |
| 12 | 107.95 | 12.7 | 203.2 |
| 13 | 114.3 | 12.7 | 203.2 |
| 14 | 120.65 | 12.7 | 203.2 |
| 15 | 127 | 12.7 | 203.2 |
| 16 | 133.35 | 12.7 | 203.2 |
| 17 | 139.7 | 12.7 | 203.2 |
| 18 | 146.05 | 12.7 | 203.2 |
| 19 | 152.4 | 12.7 | 203.2 |
| 20 | 158.75 | 12.7 | 203.2 |
A quarter inch is exactly 6.35 millimetres under the international inch definition.
The side margins leave 7.5 inches of rule length across US Letter.
A line every quarter inch makes four baseline intervals per vertical inch.
How it works
The formula
firstLine = edgeMargin + headingSpace
bottom = pageHeight - edgeMargin
if firstLine <= bottom:
writingLines = floor((bottom - firstLine) / spacing) + 1
lineY[n] = firstLine + n x spacing
otherwise:
writingLines = 0
ruledWidth = pageWidth - 2 x edgeMargin
totalRuleLength = writingLines x ruledWidth
Every length is held as an integer number of micrometres, then written to
an SVG whose width and height are declared in millimetres.
What it assumes
- Paper dimensions are trimmed physical sizes. The printer's hardware margin is not deducted; a requested line can still be clipped by a device that cannot reach it.
- The first rule is the edge margin plus the extra heading space. Heading space does not replace the blank edge margin.
- A line exactly on the bottom boundary is included, which is why a sheet can have one more rule than it has spacing intervals.
- The vertical guide is measured from the paper edge and clamped inside the horizontal writing width. Zero omits it entirely.
- Physical size is preserved only when the print dialogue uses 100% or Actual size. Fit-to-page deliberately rescales the sheet.
Common questions
Is quarter-inch ruling the same as 6 mm ruling?
No. A quarter inch is exactly 6.35 mm, so a 6 mm sheet gains more than two extra intervals over the writable height of Letter paper.
Why use SVG for printable ruled paper?
SVG stores physical dimensions and vector strokes. The rules stay sharp at printer resolution and do not depend on a screen-sized bitmap.
Sources
The full method, worked example and every assumption behind this figure are on Printable Ruled Paper Maker.