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Calcimator

Arc Length Calculator

Calculate the arc length of linear, quadratic, and circular curves between two points using numerical integration.

Inputs

Results

Arc Length

4.64678

Chord Length4.47214
Arc/Chord Ratio1.0391
How to Use This Calculator
  1. Select the curve type (linear, quadratic, or circular) and enter its defining parameters.
  2. Enter the lower and upper bounds (a and b) along the x-axis over which to measure the arc length.
  3. Arc length L = ∫[a to b] √(1 + (f'(x))²) dx; the calculator evaluates this integral numerically.
  4. For a circle segment, arc length = r × θ (radius times central angle in radians), which is computed analytically.
  5. The curve chart shows the segment of the function between the two bounds so you can visually verify the range.
  6. Arc length is always ≥ the straight-line distance between the endpoints (chord length).

How the result changes with x End

x EndArc Length
-40-1,601.39381
-15-226.14862
15226.14862
401,601.39381

What each input means

Curve Type
Type of curve to measure
Coefficient a
Leading coefficient (or radius for circle)
Coefficient b
Second coefficient (not used for circle)
x Start
Starting x value
x End
Ending x value

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Curve Type = 2, Coefficient a = 1, Coefficient b = 0, x Start = 0 = 5 input(s) provided
  2. Calculate Arc Length
    Arc Length
    4.64678 = 4.64678
  3. Calculate Chord Length
    Chord Length
    4.47214 = 4.47214
  4. Calculate Arc/Chord Ratio
    Arc/Chord Ratio
    1.0391 = 1.0391

Engine last updated . Checked against 3 independently-derived tests how we verify calculators.

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