Click for HOME
Construction Articles
All About Project33
Facts & Figures
Monthly Report
Search this Site
Helpful Tools
The P33 Toybox
Project33 Gallery
Email Project33
Klock Werks Cycles



/   -    

While I was trying to find the perfect size tire and wheel combo for Project33 I came across the formula for converting widths and heights to inches. I made a little program to get a quick calculation and thought I'd pass it along to you. It may come in handy some day. Keep in mind that the sizes are approximate and can very from brand to brand, but this will get you close. Enjoy!
transmission gear differential speed.gif tire height
I hope some of you will find this RPM-finder useful. Just take the tire height information you learn above and use the drop-down menus below to calculate your RPM's for a desired speed. Keep in mind these figures will get you close but are not exact. Only OEM automatic transmissions are listed (manual transmissions have too many variables) and the differential ratio menu contains most of the common ratios. Hope you find this useful. Let me know if there's anything else I can program to make your project easier. The answer will appear above the form.

Enter the length of wire you need (in feet) and the maximum amperage below to find the MINIMUM suggested wire gauge for a 12-Volt DC system.


This is a handy tool to calculate the suggested MINIMUM AWG (American Wire Gauge). This calculation is based on a 12-volt DC system with no more than a 0.5 voltage drop. This is only a suggestion!

NOTE: Keep in mind that 13.5 volts is typical when your engine in running and the Alternator is working correctly. Also, sizing for lighting is more critical because a voltage drop will decrease the luminous intensity of the light. A 1/2 volt drop can decrease a lamps rated luminous intensity by 20%. That means a 100 watt lamp would only be operating at 80 watts! That's why it's always wise to figure on the high side, especially when sizing wire for lighting.