The scaling ratio can be set for the Map based on the currently assigned target coordinate system. The target coordinate system defines the units that are used and can be edited as discussed in the article How can I change the units for my projection from meters to feet in Surfer?

To set the scaling ratio to 1:8000, follow the steps below:

- Click the
*Map*frame in the**Contents**window. - Click the
**Scale**tab in the**Properties**window. - Enter the 8000 in the
*Scaling ratio (1:N)*field. This specifies that N = 8000 and is the number of number of units per one inch

Surfer 13 and earlier versions did not offer a scaling ratio option so the scale had to be assigned using the Map Units per in. fields. In these cases, what to enter for the scale entirely depends on what your map X and Y units are. You will need to calculate the scale, and then enter it for the map:

- Calculate the corresponding value for your map units (see below).
- Select
*Map*in the**Object Manager**. - In the
**Property Manager**, click the**Scale**tab. - Enter the calculated X or Y scale value. For example, if you wanted 1" = 8000' and your map is in feet, you would enter 8000 to the right of
*Map units per in.*for your X or Y scale.

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**Example Calculations:**

- If your map is in units of feet, then you would simply type in 8000. So Map units per in. = 8000.
- If your map is in units of meters, then you need to do some math. 8000 feet is 2438 meters. So 1"=8000' is the same as 1"=2438 meters, and you would enter Map units per in. = 2438.
- If your map is in units of lat/long, then you need to do some slightly more complicated math. You will need to convert 8000 feet to latitude and longitude.

1° of latitude is about 68.703 miles (362751 feet). So 8000 feet is about 0.02205° latitude. Insert this for the Y scale (Map units per in. = 0.02205 for the*Y Scale*).

1° of longitude is 69.172 miles * cos(latitude). So find the latitude of the center of your map and insert it in the equation to find how many miles 1° of longitude is for your map. So if your central latitude value is 39.5°:1° longitude = 69.172 mi * cos (39.5)

= 365228.16 feet * 0.77162

= 281819 feet8000' divided by 281819 '/° = 0.02839 map units (°)

Therefore, 8000 feet is 0.02839° longitude (at 39.5° latitude). Insert this for the X scale (Map units per in. = 0.02839 for the

*X Scale*).

*Updated February 8, 2017*

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