
RATIO® Machine Heads: Revolutionizing Guitar Tuning
Every string on a guitar reacts differently to tuning adjustments, and understanding this is key to achieving perfect pitch. The thicker the core of the string, the faster it responds to changes in tension. For example, the pitch change on a plain G string is three times greater than that of the high E string, making tuning the plain G and low E strings—both with thicker cores—particularly challenging. The plain G string is also prone to going out of tune; if stretched, it can catch on the nut or slip on the string post, amplifying tension and pitch changes by a factor of two or three compared to thinner strings.
Traditional tuning methods, such as the "one-ratio-for-all-strings" approach (1:1, 16:1, 18:1), have been in use for over 300 years, relying on worm gear technology that’s over a century old. These outdated methods have left guitarists struggling with inconsistencies in tuning. RATIO® Machine Heads address these challenges by assigning a unique gear ratio to each string, ensuring that every string feels and responds uniformly, similar to the easy-to-tune B string.
How did we achieve this?
We meticulously determined the ideal gear ratios for a 360-degree rotation of the tuning knob to produce a full tone change for each string. Forelectric guitars, the gear ratios range from 39:1 to 12:1 (low to high), and we also offer options for 7-string guitars. For acoustic guitars, the ratios range from 39:1 to 12:1 (including a wound G string). Bass players can enjoy our ratios of 48:1, 36:1, 25:1, and 23:1, available for 4, 5, and 6-string configurations.
Standard guitar tuners

RATIO® guitar tuners

Standard bass tuners

RATIO® bass tuners

Standard Ukulele tuners

RATIO® Ukulele tuners

Why upgrade to RATIO® Guitar Machine Heads?
You gain precise and predictable tuning control over every string, making re-tuning, open tunings, and minor adjustments 100% faster. It's akin to driving a car with an automatic transmission—fast, smooth, and relaxed.
Transform your playing experience with RATIO® Machine Heads today!
Download your copy RATIO® guide (click a picture)
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 Machines. They’ve outdone themselves this time and 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.