KEVOS® MAKEOS · Geometry

Area of an Irregular Outline by Simpson’s Rule

What is the area of this irregular outline from measured heights at equal spacing?

Area of a plane figure of irregular outline by Simpson’s rule from up to eleven equally spaced ordinates (heights), with the trapezoidal-rule result for comparison; also gives the volume when the ordinates are cross-section areas.

Open the calculatorRuns in your browser. No account needed.

How this tool works

Inputs, units and where to find them

InputUnitTypical source
Strip width (spacing)mmEqual width of each strip.
Number of strips (even)Number of strips; Simpson’s rule needs an even number.
Heights V₀ … V₁₀ (only V₀ to V_N are used)
V0mmHeight of the figure at strip boundary 0 (or the section area for a volume).
V1mmHeight of the figure at strip boundary 1 (or the section area for a volume).
V2mmHeight of the figure at strip boundary 2 (or the section area for a volume).
V3mmHeight of the figure at strip boundary 3 (or the section area for a volume).
V4mmHeight of the figure at strip boundary 4 (or the section area for a volume).
V5mmHeight of the figure at strip boundary 5 (or the section area for a volume).
V6mmHeight of the figure at strip boundary 6 (or the section area for a volume).
V7mmHeight of the figure at strip boundary 7 (or the section area for a volume).
V8mmHeight of the figure at strip boundary 8 (or the section area for a volume).
V9mmHeight of the figure at strip boundary 9 (or the section area for a volume).
V10mmHeight of the figure at strip boundary 10 (or the section area for a volume).

Method and formulas

  1. A = (W ÷ 3) [(V₀ + V_N) + 4 (V₁ + V₃ + … + V_N−1) + 2 (V₂ + V₄ + … + V_N−2)].
  2. Trapezoidal check: A = W [(V₀ + V_N) ÷ 2 + V₁ + … + V_N−1].
  3. Entering section areas in place of heights gives a volume.
  4. Example: eight strips 10 mm wide give an area of 1,266.7 mm².

Limitations

  • Exact for curves up to the third degree between ordinates; accuracy improves with more strips.
  • Strips must be of equal width.
  • Example values are illustrations. Replace them with values for your actual task.

Typical uses

  • Find the area of a cam, template or casting outline from a drawing
  • Find a volume from equally spaced cross-section areas
  • Integrate a measured curve such as a pressure or force trace

Who it is for

  • Engineers
  • Technicians
  • Engineering students

What you get

  • Area by Simpson’s rule
  • Area by the trapezoidal rule
  • Difference between the two

Interpreting the result

  • A large difference from the trapezoidal result means more strips are needed.

References

  • Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 67–68. Topic reference; no source tables or recommended settings are reproduced.

WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.

Open the Area of an Irregular Outline by Simpson’s Rule calculator