LESSON 5 
SCALING PLANS 
HIS lesson is intended to familiarize the pupil with 
the use of scales in making and reading maps and 
plans. 
Definition 
The relation of a distance on a plan to the 
distance which it represents on the object is 
called the scale of the plan. Scales are based on the distance in 
feet on the object which is represented by one inch on the plan or 
on the number of inches on the plan which represents one foot on 
the object. In small scale plans an inch represents a considerable 
distance, often 50, 80, 100 or even several hundred feet. In medium 
scale plans an inch may represent 10, 20, 30 or 40 feet. In very 
large scale plans an inch may represent 8 or 4 or 2 or 1 feet or 
sometimes only a fraction of a foot. Odd scales, such as those in 
which one inch represents 16 or 165 or 32 feet etc. are remnants 
of the old Gunter’s or surveyors measure and are now little used, the 
decimal system being much more convenient. 
Applications 
Practically all engineers’ and landscape gardeners’ surveys and 
plans are made on a scale of one inch representing some multiple 
of ten feet. The surveys and general plans of large areas are on 
relatively small scales, the detail plans being usually on a scale of 
1” = 20’ or 1” = 40’. Occasionally plans are made to a scale of 
1” = 10’ or 1” = 30’, but these scales are not so much used. 
Architects’ plans represent smaller areas and must show more 
detail than do engineers’ plans. They are therefore usually on 
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