What scale is 1/4 inch = 1 foot?
The scale 1/4 inch = 1 foot equals a ratio of 1:48. On the drawing, 1/4 inch represents 1 foot (12 inches), so one inch of paper equals 48 inches — 4 feet — in reality. To find the ratio for any imperial scale, divide 12 by the inches-per-foot: 12 ÷ 0.25 = 48.
Source: Scale ratio (12 ÷ inches-per-foot) · Verify against your AHJ and the adopted code edition.
An architectural scale like 1/4” = 1’-0” is really a ratio of 1:48. It means 1/4 inch on the paper stands for 1 foot (12 inches) in the real world — so one inch of paper = 48 inches = 4 feet.
To convert any imperial scale to its ratio, divide 12 by the inches-per-foot:
| Scale | Ratio |
|---|---|
| 1/8” = 1’-0” | 1:96 |
| 1/4” = 1’-0” | 1:48 |
| 1/2” = 1’-0” | 1:24 |
| 1” = 1’-0” | 1:12 |
| 3” = 1’-0” | 1:4 |
So 1/4” = 1’-0” is 12 ÷ 0.25 = 48, and 1/8” = 1’-0” is 12 ÷ 0.125 = 96 (half the size, double the ratio).
Metric drawings skip the inches and state the ratio directly — 1:50, 1:100, 1:200 — which is why they’re quicker to reason about.
Work it out: the architectural scale converter turns a real dimension into its drawn size (or back) at any US or metric scale.