# Rocketry Crib Sheet (Finding height & other math)

This is a quick crib sheet to help you as you build model rockets. There is much more to be found on the Internet. If you find a helpful link please share it in the comments section below.

To Convert Inches (in) to Centimeters (cm):       (in) * 2.54 = (cm’s)

Example: 5 in * 2.54 = 12.7 cm

To Convert Feet (ft) to Meters (m):                     (ft) / 3.281 = (m)

Example: 7 ft / 3.281 = 2.1335 m

To Convert Meters (m) to Feet (ft):                     (m) * 3.281 = (ft)

Example: 30 m * 3.281 = 98.43 ft

Added 1-19-19, for a guide to build your own altitude tracker using a protractor review this guide we put together.

Updated 7-20-16, some of the links below have changed the content and no longer include the simple altitude calculation so we have added it below.

To calculate the height of a right triangle:         tan(angle) * distance = height
(yes, use a calculator to find the tangent)

Example: tan(59°) * 100 feet = 166.43 feet

Example: Sandy is launching her rocket. Her cousin, Tim, is standing 300 feet away with a protractor when Sandy launches her rocket. The protractor angle reads 127° when the rocket reaches its highest point, known as apogee. Tim knows he needs to subtract 90° from the angle on the protractor to get the correct angle. How high did the rocket go?

tan(127° – 90°) * 300 feet = height
Simplify
tan(37°) * 300 feet = height
Simplify
~0.75355 * 300 feet = height
Simplify
~226.07 feet = height

Sandy’s rocket flew about 226.07 feet in the air. (We round off the extra digits after .07)

Finding a side in a right-angled triangle

https://www.mathsisfun.com/algebra/trig-finding-side-right-triangle.html

How to measure model rocket altitude

http://www.hobbizine.com/rocketaltitude.html

Rocket Center of pressure calculator

http://physics.gallaudet.edu/tools/rocketcop.html

Rocket Altitude Calculator

http://www.unm.edu/~tbeach/flashstuff/RocketAltitudeFixedSize.html

Determine Maximum Altitude

http://exploration.grc.nasa.gov/education/rocket/rkthowhi.html

OpenRocket Model Rocket Simulator – Freeware

http://openrocket.sourceforge.net/

Altitude Tracking

http://quest.arc.nasa.gov/space/teachers/rockets/act9.html

Flight Simulator Programs (List of different software)

http://www.thrustcurve.org/simulators.shtml

#### 1 comment

• John Forshee on July 13, 2018 at 5:10 pm

Here is a cool and easy on-line calculator.
They don’t learn any math but it works slick when you need to calculate several and quickly at a group lauch.

https://www.pagetutor.com/trigcalc/trig.html