Ladder Placement Angle
Base distance for the 4:1 rule and pass/fail at 75.5 deg.
Example
You enter
- Ladder length (ft) 16
- Working height (ft) 12
You get
- Set angle 48.6 deg
- Base distance 3.00 ft
Details, formula, and sources
4:1 rule: base distance = working_length / 4. Angle θ = atan(rise / run); pass band 75-77 degrees per ANSI A14.7 / A1264.1 (target 75.5°).
ANSI A14.7 (Mobile Ladder Stands and Mobile Ladder Stand Platforms) and ANSI/ASSP A1264.1 by name; OSHA 29 CFR 1926.1053 by section.
29 CFR 1926.1053 free at ecfr.gov; ANSI standards licensed.
Estimate. AHJ and licensed professional govern.
Field names used by the API: ladder_length_ft, working_height_ft, set_angle_deg, base_distance_ft
- Pass-fail target 75.5° (4:1)ANSI A14.7