To centre by latitude and longitude, enter a latitude, followed by a comma(,) or space, and then a longitude.

• Latitude must be from 40 to 80.
• Longitude must be from -32 to -142.
• Right after centring, at the specified location you will see a 5-point star's red outline. At the bottom of the map, right beneath the map scale, you will see the latitude and longitude used for centring the map. They will be removed when the map is refreshed.

To centre by an NTS map sheet, enter the NTS sheet name as follow:

• For a 1:1M sheet, the name is a number from 0 to 120, 340, or 560 (e.g. 56). You can tag on a 2-letter quadrant (N or S, followed by E or W). For example, 56/ne or 56ne means the north east quadrant of sheet 56. The forward slash (/) preceding the quadrant tag is optional. Its presence enhances readability, especially when used in a 1:250K or 1:25K sheet name.
• For a 1:250K sheet, the name is a 1M sheet name (without a quadrant tag) followed by a letter from A to P (e.g. 56p). Note that when a 250K sheet is above latitude 68, the valid letter is only from A to H (e.g. 57h is valid, but not 57i). You can tag on a 2-letter quadrant (e.g. 56p/sw or 56psw means the south west quadrant of sheet 56p).
• For a 1:50K sheet, the name is a 250K sheet name (without a quadrant tag) followed by a number from 1 to 16 (e.g. 56p9). You can tag on a 2-letter quadrant (e.g. 56p9/nw or 56p9nw means the north west quadrant of sheet 56p9).
• For a 1:25K sheet, the name is a 50K sheet name (without a quadrant tag) followed by a letter from A to H (e.g. 56p9h). You can tag on a 2-letter quadrant (e.g. 56p9h/se or 56p9hse means the south east quadrant of sheet 56p9h).
• After centring, the map will include an NTS grid. It shows the boundary of those NTS sheets with land mass. At the bottom of the map, right beneath the map scale, you will see the NTS sheet name used for centring the map.
• We have the NTS grid for 1:1M, 1:250K, and 1:25K NTS sheets. If you centre the map by an NTS sheet of another scale or if you specify a map sheet quadrant, the NTS grid won't show the exact boundary of the specified area. To help you gauge the boundary, we also draw a 5-point star's red outline at the centre of the specified area. The star outline and the NTS grid (unless it has been selected in the layer menu) will be removed when the map is refreshed.

Following is a map of NTS sheet boundaries:

Depending on the entered NTS or co-ordinate (latitude and longitude), a scale factor will be chosen for the map. You can override that scale by entering a whole number (N). It will be interpreted to mean 1:N.

To have the main map scaled precisely for your computer display, ensure that the ruler (below the map) is measured to exactly one inch on your display. If required, drag the ruler to adjust its length.