Guitar String Tension Calculator
Calculate guitar string tension in pounds and kg-force from string gauge, scale length, and tuning frequency.
Essential for guitar setup and string selection.
Guitar string tension determines how a string feels to play and how it affects your guitar’s neck. Understanding tension helps you choose the right string gauge for your playing style and instrument.
The Physics: String tension is governed by the vibrating string equation. For a string of a given length, tuned to a specific frequency, tension depends on the string’s mass per unit length.
Simplified formula for plain steel strings: T = UW × (2 × L × f)²
Where:
- T = tension in pounds
- UW = unit weight (mass per unit length, approximated as gauge² × 0.000386 for plain steel)
- L = scale length in inches
- f = frequency in Hz
Common scale lengths:
- 25.5 inches — Fender Stratocaster, Telecaster (standard “long scale”)
- 25 inches — Paul Reed Smith (PRS)
- 24.75 inches — Gibson Les Paul, SG, ES-335 (“short scale”)
- 24 inches — Some vintage Gibsons, short-scale bass guitars
Standard E tuning frequencies (Hz):
| String | Note | Frequency |
|---|---|---|
| 1st (high E) | E4 | 329.63 Hz |
| 2nd (B) | B3 | 246.94 Hz |
| 3rd (G) | G3 | 196.00 Hz |
| 4th (D) | D3 | 146.83 Hz |
| 5th (A) | A2 | 110.00 Hz |
| 6th (low E) | E2 | 82.41 Hz |
Typical tension values for standard gauge sets on a Strat (25.5"):
| Gauge | String | Tension (lbs) |
|---|---|---|
| .009 | 1st E | ~11.5 lbs |
| .011 | 1st E | ~16.2 lbs |
| .013 | 1st E | ~21.4 lbs |
| .046 | 6th E | ~16.0 lbs |
| .052 | 6th E | ~20.5 lbs |
Most players find 14–20 lbs per string comfortable. Below 10 lbs feels very slack; above 25 lbs feels very stiff. Total set tension (6 strings) on a Strat with .010–.046 gauge is typically around 105–115 lbs. This total tension directly affects neck relief — heavier gauge strings require more neck relief or truss rod adjustment.