Tension Calculator
Use our tension calculator to learn the tension formula and to calculate tension in ropes and strings for various physics problems.
Tension in the first rope490.3325 N1× the weight of 490.333 N
Tension in the second rope490.3325 N
Weight being supported490.3325 Nstatic, so simply mg
Sum of the vertical components490.3325 Nmust equal the load exactly — this is the check that the solution balances
Horizontal components424.6404 N each wayequal and opposite, so they cancel. They do no lifting at all, yet they are what dominates the tension at shallow angles
If both ropes were at 30°490.333 N each1× the load
If both ropes were at 15°947.25 N each1.932× the load
If both ropes were at 5°2,812.967 N each5.737× the load
If both ropes were at 1°14,047.705 N each28.649× the load
Why a tightrope always sagstension diverges at zero angleas the ropes flatten, the vertical components that carry the load shrink towards nothing while the horizontal ones grow without limit. A washing line pulled truly taut would need infinite tension to stay straight under any load at all
The formula
T₁ = W cos β / sin(α+β); T₂ = W cos α / sin(α+β)
Shallow angles are dangerous
Two ropes supporting a load share it through their vertical components only. As the ropes approach horizontal those components vanish, so the tension needed to carry an unchanged weight grows without limit — at 5° each rope carries nearly six times the load, and at 1° almost thirty times.
This is why a washing line always sags, why a tow rope pulled sideways at its midpoint can free a stuck vehicle with modest force, and why rigging guides warn so strongly against shallow sling angles. The horizontal components do no lifting whatever, yet they are what dominates the tension.