String Tension Calculator
Manufacturer-agnostic tension math for guitar, bass & ukulele.
Manufacturer-agnostic tension math for guitar, bass & ukulele.
String tension is the pulling force, in pounds or kilograms, that a string puts on the neck when it is tuned to pitch. It is set by three things: the string's weight per inch, its scale length and the note it is tuned to, through the formula T = UW × (2LF)² / 386.4.
For example, a 10-46 nickel wound electric set tuned to E standard on a 25.5″ scale produces about 102.7 lbs (46.6 kg) in total. The table shows each string; the calculator above works out the same figures for any gauge, tuning and scale.
| String | Note | Gauge (in) | Type | Tension (lb) | Tension (kg) |
|---|---|---|---|---|---|
| 1 | E4 | 0.010 | Plain Steel | 16.3 | 7.4 |
| 2 | B3 | 0.013 | Plain Steel | 15.5 | 7.0 |
| 3 | G3 | 0.017 | Plain Steel | 16.6 | 7.6 |
| 4 | D3 | 0.026 | Nickel Wound | 18.4 | 8.3 |
| 5 | A2 | 0.036 | Nickel Wound | 19.0 | 8.6 |
| 6 | E2 | 0.046 | Nickel Wound | 16.9 | 7.7 |
Heavier gauges, longer scales and higher notes all raise tension; tuning lower reduces it. See the Methodology for sources and validation, or browse the tension charts for common sets and tunings.
There's no single universal number. It depends on gauge, tuning, scale length, and construction. As a rough reference, a standard 10-46 electric set in standard tuning at 25.5" scale runs about 15-19 lbs per string; a typical 45-100 bass set at 34" scale runs roughly 35-48 lbs per string. Use the calculator above for your actual setup rather than relying on a rule of thumb.
T = UW × (2LF)² / 386.4, where T is tension in pounds, UW is the string's unit weight in lb/in, L is scale length in inches, F is the target pitch in Hz, and 386.4 is standard gravitational acceleration. See the Methodology page for the full derivation and sourcing.
For the same note and scale length, yes, heavier gauge means more unit weight, which means more tension. But tension also depends on scale length and target pitch, so a heavier string tuned lower, or on a shorter scale, can end up at lower tension than a lighter string tuned higher on a longer scale.
Common defaults: 25.5" for most electric/acoustic guitars (Fender-style), 24.75" for many Gibson-style guitars, 34" for standard long-scale bass, and around 13-15" for soprano/concert ukulele. Measure from the nut to the bridge saddle for an exact figure, since it matters more than most of the other inputs.
Small differences (typically under 2%) come from rounding in published charts and minor differences in assumed material density. This calculator's plain-string and phosphor-bronze predictions are validated to within 1% of published D'Addario reference charts. See the Methodology page for the full validation numbers, including where accuracy is lower (certain wound constructions without a published reference table).
Yes. Higher tension generally feels stiffer under the fingers and can add clarity and sustain; lower tension feels looser and can be easier to bend but may feel floppy or buzz more easily. Tension balance across a set (not just the total) also affects how even the instrument feels string to string, which is what the calculator's balance check flags.