Starrett Pro-Site Miter Protractor
Cutting miters accurately is always a challenge. Eachtime you measure a wall angle and calculate a saw setting, there's potential for error. Starrett's Pro-Site Miter Protractors take the angle calculations out
of cutting inside and outside miters, angled butt joints and crown molding. They'll help you create perfect joints every time.

Starrett 505-series Dial
Basic 505-Series Protractors
All three models of the basic 505-series protractors are functionally the same. For cutting a simple miter or angle joint, the saw settings are directly on the tool - use the inside scale & outside arrow for
for miters and the outside scale & inside arrow for single cuts. If you're cutting crown molding flat on the table of a sliding compound miter saw, measure the angle and use the provided chart
to set the bevel and miter angles.
What are the differences between the 505-series models then?
- The 505A-12 is a hefty 12" long by 2-1/2" wide by 1/4" thick chunk of aluminum (each leg). It will stand up to the rigors of just about any jobsite. It's made in the USA.
- The 505A-7 is also aluminum, but it's only 7" long. It's just as tough as it's bigger brother, but it's small enough to fit in your apron pocket. It's made in the USA.
- The 505P-7 is plastic version of the 505A-7. It fits nicely in your pocket, but probably won't stand up to the tough environment of a jobsite. It's perfect for the home woodworker or DIY home improver. It's made in China.
If you would like to carry the 505A-12 on your belt, we offer a leather holster.
See the video below for a demonstration of this protractor.
CP505A-12 5-in-1 Protractor
The CP505A-12 is an improved version of the basic 505A-12. It's also 12" long aluminum and made in the USA. It does all of the same things that the 505A-12 does, but has added these features.
- The back has an additional protractor that reads 0°-180°-0° & 180°-0°-180°.
- The crown molding chart is mounted on the inside leg of the protractor so you can never misplace it.
- The inside of the other leg also includes a quick reference guide for setting standard roof pitches.
If you would like to carry the CP505A-12 on your belt, we offer a leather holster.
CP505E-12 Electronic Protractor
The CP505E-12 takes all of the functions of the CP505A-12 and fits them into one electronics-enabled tools that eliminates all charts and calculations. Crown molding is a breeze. Set the spring angle of the
crown molding, measure the wall angle and the tool will tell you the spring & miter angles with the touch of a button! It doesn't have the crown molding or roof pitch charts, but that's just because you
don't need them! All of the calculations are done for you.
The CP505E-12 includes a nylon case/holster and instruction sheet. If you would prefer a holster upgrade, we also offer a leather holster.
See the video below for a demonstration of this protractor.
Videos
Starrett 505-series Miter Protractors
CP505E-12 12" Electronic Protractor
Starrett 505-series Miter Protractors
505P-7 Protractor as demonstrated by Ron Hazelton -- the fastest, easiest and the most accurate way to crown molding. This new approach to crown molding helps user get rid of bevel gage and the confusing
calculations. Starrett 505P-7 Protractor measures the angle of the wall and indicates the miter angle without any calculations! The prcodures are the same for the 505P-7, 505A-7 & 505A-12 protractors.
CP505E-12 12" Aluminum Electronic Combination Protractor
The Starrett CP505E-12 Electronic Combination Protractor simplifies crown molding work and and virtually eliminates errors, Featuring Ron Hazelton.
Additional Information
Starrett Crown Molding Guide for the 505A-12, 505A-7 & 505P-7
Starrett Crown Molding Guide for the CP505A-12