Catenary Curve Calculator

Use the Catenary Curve Calculator to compute the equation, vertex, arc length, and sample points of a catenary y = a·cosh((x−h)/a) + k for any parameters a, h, and k.

837.6K uses Updated · 2026-05-05 Runs locally · zero upload
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How to Use Catenary Curve Calculator

The Catenary Curve Calculator lets you explore any catenary curve by specifying its three parameters. The calculator instantly shows the equation, the vertex (lowest point), and a table of sample coordinates.

  1. Enter parameter a — This must be a positive number. It controls the scale and curvature of the catenary. The default value 1 gives the standard catenary.
  2. Enter horizontal shift h — Moves the vertex left (negative h) or right (positive h) along the x-axis. Default is 0.
  3. Enter vertical shift k — Moves the entire curve up or down. Default is 0.
  4. Evaluate at a specific x — Optionally enter an x value to compute the y coordinate of the point on the catenary.
  5. Compute arc length — Optionally enter x₁ and x₂ to compute the length of the curve between those two x values.
  6. Read the sample table — The Catenary Curve Calculator generates a table of (x, y) pairs symmetrically around the vertex for a visual overview.

Formula & Theory - Catenary Curve Calculator

The Catenary Curve Calculator uses the general form of the catenary equation:

y = a · cosh((x − h) / a) + k

where the hyperbolic cosine is defined as:

cosh(t) = (eᵗ + e⁻ᵗ) / 2
SymbolMeaning
aScale parameter (a > 0); related to the tension-to-weight ratio of the chain
hHorizontal position of the vertex
kVertical position of the vertex
xThe independent variable (horizontal position)
yThe height of the curve at position x

Vertex (lowest point): The vertex is always at (h, a + k).

Arc length formula:

s = a · [sinh((x₂ − h)/a) − sinh((x₁ − h)/a)]

where sinh(t) = (eᵗ − e⁻ᵗ)/2 is the hyperbolic sine.

Physical Interpretation

The catenary arises in physics because a hanging chain minimizes its potential energy subject to fixed endpoints and fixed length. The parameter a = T/ρg, where T is the horizontal tension in the chain, ρ is the linear mass density, and g is gravitational acceleration.

Assumptions and Limits

The Catenary Curve Calculator assumes a uniform chain or cable with no stiffness (perfectly flexible). Real cables deviate slightly due to bending stiffness and wind loads. For very large x/a ratios, the exponential in cosh and sinh may overflow floating-point limits; the calculator will display “undefined” in such cases.

Use Cases for Catenary Curve Calculator

The Catenary Curve Calculator is useful across mathematics, physics, and engineering:

  • Bridge and cable design — Approximate the shape of suspension cables, power lines, and anchor chains using the catenary equation.
  • Architecture — Inverted catenaries are the optimal arch shape for pure compression structures, as famously used in the Gateway Arch in St. Louis.
  • Mathematics education — Study hyperbolic functions (cosh, sinh) in a real-world context and see how they differ from circular trigonometric functions.
  • Physics problems — Solve hanging-chain problems in classical mechanics by fitting the catenary equation to given boundary conditions.

The Catenary Curve Calculator makes it easy to explore the mathematical beauty of this curve and apply it to practical engineering and scientific calculations.

Frequently asked questions about Catenary Curve Calculator

What is a catenary curve?

A catenary is the shape that a flexible, inextensible chain or cable takes when hanging freely under its own weight between two supports. Its equation is y = a·cosh(x/a) in the standard position, where a is a positive scaling parameter.

What does the parameter a control in the Catenary Curve Calculator?

The parameter a determines how wide or narrow the catenary is. A larger a gives a flatter, wider curve; a smaller a gives a tighter, more steeply rising curve.

How does the Catenary Curve Calculator compute arc length?

The arc length formula is s = a·[sinh((x₂−h)/a) − sinh((x₁−h)/a)]. Enter x₁ and x₂ in the optional section to compute the arc length between those two points.

Is my data stored?

No. All calculations happen in your browser; nothing is sent to a server.