The Pole-to-Dial Converter-Calculator

Use the "Pole-to-Dial Converter-Calculator" to convert any vertical pole (e.g., a flagpole, utility pole, etc.) into a fully functional reduced horizontal sundial featuring declination lines ("date curves") for the equinoxes and solstices.

Enter your latitude and gnomon height (pole height) below, then click on the "Calculate!" button. The Pole-to-Dial Converter-Calculator will calculate all of the hour angles and distances that you need to construct the date curves on your sundial.

To find your latitude and longitude, consult a good map or visit:

CAUTION: This table will not work well for latitudes smaller than 4 degrees.

Enter your latitude in degrees
(positive values only):

Enter gnomon height (unit-independent)
(positive values only):

Distance CG: units
Recommended minimum dial plate radius: units
Hour Line Angles B
12 noon:
degrees
11 am, 1 pm:
degrees
10 am, 2 pm:
degrees
9 am, 3 pm:
degrees
8 am, 4 pm:
degrees
7 am, 5 pm:
degrees
6 am, 6 pm:
degrees

Date Curve Points
? Distance CS Distance CE Distance CW
12 noon:
units units units
11 am, 1 pm:
units units units
10 am, 2 pm:
units units units
9 am, 3 pm:
units units units
8 am, 4 pm:
units units units
7 am, 5 pm:
units units units
6 am, 6 pm:
units units units

These are general illustrations for your guidance. The patterns you see are not drawn for the latitude you entered.

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