How to Make a Map for an Architect Scale

Determine the architectural scale you would like to use for the map or site plan. In the scale, a fraction of an inch equals 1 foot. The standard scales on an architect's scale are: 1/32 inch, 1/16 inch, 3/32 inch, 1/8 inch, 3/16 inch, 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inch, 1 1/2 inches and 3 inches. For example, if 1/32 inch equals 1 foot, a 1/32 inch on the scale or a ruler equals a distance of 1 foot in real space.

Draw the map at this scale using the fraction you have chosen to represent a true distance of 1 foot, or scale a map to the architectural scale using a photocopier.

If you must rescale an existing map, calculate the increase or decrease of the scale by dividing the desired fraction by the existing fraction. For example, if you want 1/8 inch to equal a foot in your map and the existing map shows that 3/32 inch equals a foot, you need to divide 1/8 by 3/32. This provides the approximate result of 1.33, which is 1 1/3. Therefore, you would scale the drawing on a copier 133.3 percent to make the scale change to 1/8 inch equals a foot.

Similarly, an existing scale of 12 inches equals 1 foot, or a true scale, would be divided by 1/8. 1/8 divided by 12 equals 1/96 or approximately 0.0104. Quotients that are a fraction of 1, as 1/96 is, mean the drawing must scaled down or decreased 96 times or 9600 percent.

Many photocopiers cannot scale more than 200 percent. If this is the case, divide the total percentage by the photocopier's maximum change of scale continuously until your quotient is equal or less than the photocopier's maximum. In the example above, most copiers will not decrease the scale 9600 percent. Instead, you would do multiple reductions---6 times at 200 percent and 1 time at 150 percent, because 9600 percent equals 200 percent times 200 percent times 200 percent times 200 percent times 200 percent times 200 percent times 150 percent. In other words, 96 equals 2 times 2 times 2 times 2 times 2 times 2 times 1.5; or 2 to the sixth times 1.5.

Check the dimensions on the correctly scaled map to the existing map or space. Again, use the architectural scale to determine the measurement on the new or resized map. For example, 6 feet in reality will equal 3/4 inch on a map with a scale of 1/8 inch equals 1 foot.

Double-check your dimensions; it is easy to make a mistake when working with multiple scales.