Using the Scale Solar System calculator

Want to build or have your students make a scale solar system? Really having problems figuring out the sizes and distances? This Excel spreadsheet can help.

For those of you without Excel, Iím sorry. I am working on a program to do the same thing so that anyone can use it. Check back.

Solar System scale models help students (and many adults) visualize the size of our solar system. Since we are working with such large sizes and distances it is very hard for anyone to really grasp it. With a scale model and some good explanations this begins to come clear. I do a whole series of activities to help get this concept across that can last from 30 minutes to an hour. This spreadsheet allows me (or you) to quickly adjust to my setting and the materials available.

Ideally, with older students, you should let them figure out how to make this work. Beginning with the scale Sun, or a planet, and figure out the sizes and distances to the rest. They might think that their results are wrong since the reality can be quite surprising. You can quickly check their results by plugging a number into the spreadsheet. Who wants to do all that math anyway?!

The actual size and distance numbers are rounded. They are not to the nearest mile or kilometer. The distances are average distances. The planets do not have perfectly circular orbits and Pluto has a very irregular orbit that sometimes takes it inside of the orbit of Neptune. This wonít happen for about another 300 years.

To use the spreadsheet:

Open it in Excel.

Put the size of the Sun you want to use in the red box at the top. Press ENTER. The numbers for scale size and distance will update. Use the English or Metric system as you wish. These two are not linked and an entry into one will not update the other.

The spreadsheet is protected so you will not be able, on purpose or by mistake, change the formulas.

If you find a problem with this spreadsheet please let me know. And, be kind. After all itís free!



You can have your students create a solar system on a strip of adding machine tape. This works great to help visualize the distances to planets, but canít really show the sizes of the planets at the same time, UNLESS, you make it really long. Quite a challenge in that case.

Enter .01 into the metric Sun size. Press ENTER to get the figures to update. Now you have the distance to the planets in millimeters. With most students it might be easier to give the measurements in centimeters. (Move the decimal one place to the left to get centimeters.)

Your Sun is now 1 cm in diameter and you can read the diameters of the other planets on the chart. You will find that many will read 0.00. This means that the planet diameter is smaller than a hundredth of a millimeter!

Play around with different sun sizes in either English or metric. The size suggested above uses about 4 Ĺ meters of tape.

I have used this with 3rd graders through adults. They are always amazed!


LINK to Spreadsheet HERE.  (right click and "save as" to retrieve a copy.)


If you want to see the scale solar system with distances and sizes all set up visit:

The Sagen Planet Walk in Ithaca, New York. Dedicated to Carl Sagen who was a professor at Cornell University.

(at this writing, 5/2002, the web link to this site was not working)


The Foster Planet Walk in Grand Rapids, Mich.


Rev. Dr. Ernest F. Andrews Memorial Planet Walk, Allentown, PA.


University of Delaware University Gallery, Newark, Delaware


Search the internet for more. There are lots!