This cable force calculator finds the tension in two symmetric support cables that hold a hanging load. Enter the load weight and the cable angle above to get the tension in each cable.
Formula (two symmetric cables)
T = W ÷ (2 × sin θ)
θ is the angle each cable makes with the horizontal. Shallower angles sharply increase the tension.
Example
W = 1000 N, θ = 30°: T = 1000 ÷ (2 × sin 30°) = 1000 N per cable.
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Frequently Asked Questions
How do I calculate cable tension?
For two symmetric cables, divide the load by twice the sine of the cable angle: T = W / (2 sin theta).
Why does a shallow cable angle increase tension?
As the angle drops, sin theta shrinks, so the tension rises sharply — nearly horizontal cables carry huge loads.
Does each cable carry half the load?
Only when the cables are vertical. At an angle, each carries more than half because of the geometry.