Convert Pixels per millimetre to Pixels per foot
Convert Pixels per millimetre (px/mm) to Pixels per foot (px/ft) instantly and accurately.
Conversion Formula
px/ft = px/mm × 304.8
About Pixels per millimetre
The pixel per millimetre (px/mm) is the resolution unit of precision in machine vision, flatbed scanning, and microscopy, where working distances are in millimetres. Industrial camera datasheets (Basler acA5472-17um, FLIR BFS-U3-200S6M-C) specify resolution in px/mm at defined field widths; a 20 MP sensor over a 100 mm field resolves 54.96 px/mm. ISO 12654 (archival scanning) specifies minimum 8 px/mm (≈ 200 PPI) for standard digitisation and 24 px/mm (≈ 600 PPI) for fine-detail originals. Digital pathology: Leica Aperio GT450 at 40× magnification achieves ≈ 4,405 px/mm. CMOS sensor pixel pitch has shrunk from 7.4 µm/px (≈ 135 px/mm, mid-2000s) to 0.64 µm/px (≈ 15,625 px/mm) for smartphone sensors in 2024. Since 1 in = 25.4 mm exactly, 1 px/mm = 25.4 PPI exactly. A 300 PPI photo print = 300/25.4 ≈ 11.81 px/mm.
About Pixels per foot
The pixel per foot (px/ft) is an imperial resolution unit used in architectural visualisation, large-format display engineering, and document scanning where distances are measured in feet. The foot is exactly 0.3048 m = 12 in (international foot, 1959), giving 1 px/ft = 1/12 PPI ≈ 0.08333 PPI. Microfilm scanners for engineering drawing digitisation (ANSI/AIIM MS23) are specified in px/ft; a 200 px/ft scan of a 24-inch D-size drawing yields 400 pixels across the 2-foot width. Outdoor LED walls at P6 pixel pitch (6 mm) covering one foot ≈ 50.8 px/ft. Building plans at 1:48 scale reduce 1 actual foot to 0.25 in on paper, requiring ≥ 3 px/ft for legibility. 1 px/ft = 1/12 PPI ≈ 0.083333 PPI ≈ 3.281 px/m.
Quick Reference Table
| Pixels per millimetre (px/mm) | Pixels per foot (px/ft) |
|---|---|
| 1 px/mm | 304.8 px/ft |
| 2 px/mm | 609.6 px/ft |
| 5 px/mm | 1524 px/ft |
| 10 px/mm | 3048 px/ft |
| 25 px/mm | 7620 px/ft |
| 50 px/mm | 15240 px/ft |
| 100 px/mm | 30480 px/ft |