Published formula
T = UW × (2 × L × F)² ÷ 386.4, where T is pounds-force, UW is pounds per linear inch, L is scale length in inches, and F is frequency in hertz.
The matcher uses a limited subset of D’Addario XL published unit weights. It does not infer unit weight from diameter and does not claim that another brand or construction has the same tension.
Working limits
Scale is the vibrating length. Tuning frequency must match the intended octave. Results use ideal-string reference data; installation, construction tolerance, speaking length, and measurement conditions introduce differences.
Scope of this reference
Understand unit weight, scale length, frequency, units, and the supported data boundary. Use Guitar String Tension Formula Reference to make a repeatable decision for this named task, not to impose one specification on every instrument.
Practical example
At fixed unit weight and scale, dropping one whole step multiplies frequency by about 0.891 and tension by about 0.794. Exact comparisons between products still require their published unit weights; diameter alone cannot supply the missing construction data.
Record the conditions
For Guitar String Tension Formula Reference, write down instrument type, tuning, installed strings, relevant hardware, climate when material, physical datum, unit, tool resolution, and the result before and after change. A result from this reference is comparable only when its method travels with the number.
Verification checklist
- For Guitar String Tension Formula Reference, confirm the starting state and exact question.
- Repeat its critical measurements from the same reference.
- Compare its result with direct observation and applicable maker documentation.
- Change one reversible variable where the task permits.
- Retest the named symptom and preserve unresolved exceptions.
Related workflow
- string tension matcher — continue when that page answers the next unresolved measurement or decision.
- alternate tuning string selector — continue when that page answers the next unresolved measurement or decision.
Limits
Guitar String Tension Formula Reference cannot inspect hidden structure, material condition, service history, or player technique. Stop this reference workflow for electrical hazards, abnormal resistance, structural movement, conflicting readings, or unplanned material removal.