
The simple genius behind RATIO® multi-geared machine heads
RATIO® Machine Heads provide high-performance tuning for your guitar. Each string has a unique gear ratio tailored for its core tension, ensuring precise tuning. RATIO’s patented technology offers individual tuning gears for every string, allowing for fine adjustments on thicker strings (like the G and Low E) and coarser tuning on thinner ones, with ratios ranging from 12:1 to 39:1. With RATIO® installed, one full turn of the knob equals about one tone for each string, making tuning fast, precise, and intuitive.

The fastest, most precise tuning in the universe!

Install RATIO® faster, without having to drill or fill holes with InvisoMatch® Adapter Plates!
InvisoMatch® Adapter Plates for RATIO® Tuned Machine Heads are the easiest approach to installing RATIO® Tuned Machine Heads on your guitar. Simply select the installation plate design that matches the screw/pin hole location of your factory installed machine heads, then just use the existing screws holes, no holes to drill or fill. You’ll be up and running within minutes, with perfectly installed and aligned set of RATIO’s . Stay classy you axe master.
Predictable, precise tuning, retuning and open tunings
RATIO® tuning feels natural. You don't have to think about which string you are tuning because they all feel and respond the same. No more overshooting the Low E or plain G. No more twisting away on the High E or D string. Open tunings have never been easier. String gauges such as light top, heavy bottom are no problem with RATIO®; they still do the same precision tuning..
Not just another machine head
RATIO® is more than just another entry into the machine head market. Instead, RATIO® has reinvented how machine heads function with the musician.
Once you Experience our RATIO® tuned machine heads, you won't go back!
“They are on my personal guitar. They’re great, I can’t believe no one had come up with this idea until now! Makes tuning effortless and easier!”
JAMES VALENTINE
MAROON 5
“Having been a user of Graph Tech products for years, I’m blown away by the Ratio Tuning Machines. They’ve outdone themselves this time and these things are going on EVERY guitar I own.”
JASEN RAUCH
BREAKIN BENJAMIN
“I didn’t know tuning my bass could be a recognizably better experience. I love the Ratios, and they’re so smooth!”
NICOLE ROW
PANIC! AT THE DISCO
"I am pleased to announce that my guitars are now have Ratio locking Tuners. The Ratio locking Tuners are fantastic, and being out of tune is a thing of the past thanks to these Tuners.
MICK BOX
URIAH HEEP
Graph Tech has created some of the world's most recognized products and brands in the music industry
The list of industry firsts include the world's first self-lubricating nut in 1983, String Saver Saddles the first saddle to drastically reduce string breakage, TUSQ man-made ivory, and Ratio machine heads.