Tension Calculator
Calculate the tension force in a rope or cable supporting or accelerating a hanging mass.
What tension is
Tension is the pulling force transmitted through a rope, cable, or string when it is pulled taut by forces acting on it from opposite ends. It is a reaction force that keeps a hanging or accelerating object in equilibrium (or produces its acceleration).
The formula used
For a mass hanging straight down (or accelerating vertically), tension is T = m(g + a), where a is upward acceleration (zero for a stationary or constant-velocity load, negative for downward acceleration). If the rope hangs at an angle from vertical, the calculator divides by cos(θ) since only the vertical component of tension supports the weight.
This calculator treats the rope as massless and inextensible, with a single point of support. For general physics education purposes.