🎸 String Tension Calculator
Enter a string's unit weight, your scale length, and the target pitch to see the static tension it pulls at — the fast way to balance a custom set or plan an alternate tuning.
🎸 Calculate String Tension
What is a String Tension Calculator?
It turns three numbers — a string's unit weight, your instrument's scale length, and the pitch you want to tune to — into the static tension that string will pull at. That figure is the backbone of building a balanced set, comparing gauges, and planning drop or alternate tunings.
The maths follows the D'Addario formula used across the industry. Pull unit weights from a manufacturer's chart for the exact string, and treat the answer as a well-grounded estimate to confirm on the instrument before you commit.
❓ Frequently Asked Questions
How does the string tension calculator work?
It uses the standard D'Addario relation: tension (in pounds) equals the string's unit weight multiplied by the square of (2 × scale length × frequency), divided by 386.4. Enter the string's unit weight in pounds per inch, your instrument's scale length in inches, and the target pitch in hertz, and it returns the static tension that string will pull at when tuned to that pitch.
Where do I find a string's unit weight?
String manufacturers publish unit-weight charts (pounds per inch) for every gauge and construction in their range. Look up the exact string you plan to use — plain steel, nickel-wound, phosphor bronze, and flatwound strings of the same diameter differ — and use that figure for an accurate result.
What frequency should I enter?
Enter the fundamental frequency of the note you want that string tuned to. For standard tuning, the low E is about 82.41 Hz, A is 110 Hz, D is 146.83 Hz, G is 196 Hz, B is 246.94 Hz, and the high E is about 329.63 Hz. Drop and alternate tunings simply use the frequency of the new target note.
Why does string tension matter?
Balanced tension across a set makes an instrument feel even and play in tune, while total tension affects neck relief and how the guitar responds. Checking tension helps you build a custom set, compare gauges, or plan a drop or alternate tuning without over- or under-tensioning the neck. Treat the result as a guide and confirm against manufacturer data.