Guitar String Tension Calculator — String Force in N and lbs
The tension a guitar string exerts on the nut and bridge depends on its diameter, the vibrating length (scale length), the target pitch, and the string material. Enter those four values to get the tension in Newtons, pounds-force and kilogram-force — useful when comparing string gauges or setting up custom tunings.
mm
mm
Hz
String material
Tension in Newtons — the pulling force on the nut and bridge
- 1
Linear density μ
7,850 kg/m³ × π × (0.165 mm ÷ 1000)² = 0.6714 g/mMass per metre of the string — set by its material density and cross-section area. - 2
Wave factor 2Lf
2 × 0.648 m × 329.6 Hz = 427.16 - 3
String tension
0.000671 kg/m × 427.16² = 122.5
How does this calculator work?
Guitar string tension T = μ × (2Lf)², where μ = ρ × π × (d/2)² is the linear density. Enter the string diameter (mm), scale length (mm), tuned frequency (Hz) and material to get the tension in Newtons and pounds. Valid for plain/monofilament strings; wound strings need manufacturer unit-weight data.
Formula
How this is calculated
A guitar string under tension vibrates at a fundamental frequency determined by the wave equation: f = (1/2L) × √(T/μ). Rearranging gives T = μ × (2Lf)², where μ is the linear density of the string (mass per unit length in kg/m), L is the vibrating scale length in metres, and f is the target pitch in Hz. For a plain solid string, μ = ρ × π × (d/2)², where ρ is the material density in kg/m³ and d is the string diameter in metres.
This calculator uses published densities for common plain-string materials: steel music wire (≈ 7 850 kg/m³), 80/20 bronze alloy (≈ 8 600 kg/m³), and monofilament nylon (≈ 1 150 kg/m³). Results are valid for plain, solid-cross-section strings. Wound strings (hex or round core wrapped with a thinner wire) cannot be modelled from diameter alone — their effective linear density depends on the core-to-wrap ratio, and manufacturers publish measured unit-weight values for those strings.
Typical tensions for a six-string guitar in standard tuning range from about 40 N (9 lbs) on the thinnest treble string to 100+ N (22+ lbs) on the thickest wound bass string; a full set usually totals 400–600 N. High tension aids intonation and sustain; low tension improves playability at the cost of tone. Use the calculator to compare gauges numerically before buying.
Frequently asked questions
A standard electric guitar set in standard tuning typically exerts 40–90 N (9–20 lbs) per plain string. Acoustic sets run higher — 70–110 N (15–25 lbs) per string — because acoustic guitar tops need more vibration energy. A full set totals roughly 400–600 N across all six strings.
Tension scales with the square of frequency (T ∝ f²). Dropping one semitone (ratio ≈ 0.944) reduces tension by about 11%; dropping a full step reduces it by roughly 21%. This is why detuned guitars need heavier gauges to maintain similar feel and tone.
Not accurately from diameter alone. Wound strings have a steel or composite core wrapped with a separate wire, so their effective linear density differs greatly from a solid cylinder of any single material. For wound strings, use the unit-weight data from your string manufacturer's published tension chart.
Also known as
TG we-Calculate Editorial Team. (2026). Guitar String Tension Calculator — String Force in N and lbs [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/guitar-string-tension-calculator
TG we-Calculate Editorial Team. "Guitar String Tension Calculator — String Force in N and lbs." TG we-Calculate. 2026. https://we-calculate.com/calculator/guitar-string-tension-calculator.
TG we-Calculate Editorial Team, "Guitar String Tension Calculator — String Force in N and lbs," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/guitar-string-tension-calculator
@misc{wecalculate_guitar_string_tension_calculator, title = {Guitar String Tension Calculator — String Force in N and lbs}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/guitar-string-tension-calculator}}, year = {2026}, note = {TG we-Calculate} }
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