String Tension Calculator
Calculate guitar and bass string tension from gauge, scale length and pitch.
About this tool
The String Tension Calculator estimates the pull a guitar or bass string places on the neck from its gauge, scale length and tuned pitch. Enter the diameter (inches or mm), the scale length in inches, and either a note name or a frequency in Hz, then choose plain or wound. It returns tension in pounds and kilograms, the derived unit weight, and a note-to-frequency reference at A4 = 440 Hz. Ideal for luthiers and players planning custom string sets, alternate tunings or balanced-tension setups.
Frequently asked questions
How is string tension calculated?
Tension equals the string's unit weight times (2 x scale length x frequency) squared, divided by 386.4. Heavier gauges, longer scales and higher pitches all raise tension.
Can I enter gauge in millimetres?
Yes. Add an mm suffix, e.g. gauge=1.17mm, and the tool converts to inches. Otherwise the gauge is read as decimal inches like 0.046.
Are wound-string results accurate?
Plain steel results are accurate to within about a percent. Wound strings have a lighter wrap over a thin core, so the calculator's solid-wire estimate runs slightly high and is marked approximate.