Sign type, size class, legend and lines converted into legend length, panel width and height, border and spacing (FAA AC 150/5340-18H).
Pick the sign type and size class, then type the legend. Characters, arrows and cell dividers are laid out using editable width and spacing ratios, giving the minimum panel width, the fabrication width and a to-scale preview. Size-class heights follow the AC; character widths and gaps are nominal ratios you can replace with the AC appendix or manufacturer values.
Characters A–Z, 0–9 and “-”. Arrows: [L] [R] [U] [D] [UL] [UR] [DL] [DR] (or ← → ↑ ↓ ↖ ↗ ↙ ↘). “|” = cell divider; a space = word gap.
Schematic only: glyphs are stretched to the calculated widths and are not the AC letter outlines. Use it to check proportions and fit.
Dimensions are shown in mm and inches.
Schematic only: glyphs are stretched to the calculated widths and are not the AC letter outlines.
Quick answers on turning a sign legend into panel width, height, border and spacing.
You pick the sign type and size class, then type the legend, and it converts them into legend length, panel width and height, border and spacing, following FAA AC 150/5340-18H. Characters, arrows and cell dividers are laid out using editable width and spacing ratios, giving the minimum panel width, the fabrication width and a to-scale preview.
Use one line per row, up to 3 rows. Characters are A to Z, 0 to 9 and the hyphen. Arrows are written as [L], [R], [U], [D], [UL], [UR], [DL] and [DR], or with arrow symbols. A vertical bar is a cell divider and a space is a word gap.
Size 1 has a legend height of 305 mm (12 in) on a 460 mm (18 in) panel. Size 2 has 460 mm (18 in) on a 610 mm (24 in) panel, and Size 3 has 610 mm (24 in) on a 760 mm (30 in) panel. The top and bottom margin is the panel height minus the legend height, divided by 2, about 76 mm for all three sizes. Stroke width is taken as the legend height divided by 6, and the border as about 0.04 times the legend height. You can also choose a custom height.
The legend length is the sum of each character or arrow width ratio times the legend height, plus the gaps between neighbours, which depend on whether they are characters, arrows, dividers or word gaps. The minimum panel width is the legend length plus the side margins and the border. The fabrication width rounds that up to your width step, and the extra width is split equally each side.
The width is set by the longest line and each line is centred. The panel height is the number of lines times the legend height, plus the line gaps and the vertical margins. A panel taller than the size-class panel height is flagged, because the standard panel height only covers one line.
No. The size-class heights follow the AC, but character widths and gaps are nominal ratios that you can replace with the AC appendix or manufacturer values. The preview is schematic only, with glyphs stretched to the calculated widths, and it is not the AC letter outlines. Use it to check proportions and fit.
Yes. Add each sign to the schedule, then download it as a CSV, copy a summary, or print or save it as a PDF. Dimensions are shown in mm and inches. You can load examples or clear the schedule.
It does not draw AC letter outlines, set legend content or check the minimum size class against runway visibility. It does not size legs, frangible couplings or the electrical load, so use the Sign BOQ and Transformer VA tools for those. It is a planning and layout aid. Legend sizes, character shapes, spacing and colours must be taken from the current FAA AC 150/5340-18 or ICAO Annex 14 as adopted for the project, and from the approved manufacturer drawing.
Each legend line is split into characters, arrows, dividers and word gaps. Widths and gaps scale with the legend height h, so the same layout holds for every size class.
| Size | Legend h | Panel height |
|---|---|---|
| 1 | 305 mm (12 in) | 460 mm (18 in) |
| 2 | 460 mm (18 in) | 610 mm (24 in) |
| 3 | 610 mm (24 in) | 760 mm (30 in) |
Single-line panels use the standard panel height. The top and bottom margin is (panel − legend) ÷ 2, about 76 mm for all three sizes. Stroke width is taken as h ÷ 6 and the border as about 0.04 h.
wi is the width ratio of each character or arrow. The gap depends on the neighbours: character to character, character to arrow, around a divider, or a word gap.
mh is the side margin ratio and b the border width (types that carry a border). The fabrication width rounds up to your step, and the extra width is split equally each side.
The width is set by the longest line and each line is centred. A panel taller than the size-class panel height is flagged, as the standard panel height only covers one line.
It does not draw AC letter outlines, set legend content or check the minimum size class against runway visibility. It also does not size legs, frangible couplings or the electrical load: use the Sign BOQ and Transformer VA tools for those.
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