How to Design a Sundial

Choose your materials. You'll need at least two pieces of paper, cardboard or wood. If you're making it out of wood, you'll also need a saw, wood glue and a wood sealant (if you want to keep your sundial outside.) For basic presentable sundial, use two pieces of cardboard. Other usable materials include plastic, styrofoam or metal.

Find the approximate latitude of your location. Do this using an online map and selecting your location.

Design the gnomon, or the straight-edged blade that casts a shadow to tell time. Using the protractor, draw an angle based on your latitude. For example, if you're near Ottawa, Ontario, you'll make a 45 degree angle; if you're near Jacksonville, Florida, you'll make a 30 degree angle. The piece can be triangular or rod-like as long as the angle is fairly accurate.

Draw the sundial's markings. You'll need to use an online sundial line calculator to get the correct angle measurements for your latitude. Draw these markings yourself without a calculator by drawing a 180 degree arch, and drawing a line perpendicular to the base at its center; label this latter line as 12 p.m. Attach the gnomon so that it overhangs this arch and is aligned parallel to the noon line. Using a calibrated stopwatch, mark off where the lower end of the gnomon casts a shadow each hour.