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Numerical Integration Calculator

Compare trapezoidal rule, Simpson's rule and Gauss–Legendre quadrature for any integral, with each method's error.

Enter values

Results update as you type.

Result

Best estimate (adaptive)

3.241309263195

Method comparison

MethodValueError
Trapezoidal3.2480.006674
Simpson's3.2413-0.00002959
Gauss–Legendre (5-pt)3.2413-2.62 × 10^-13

About the Numerical Integration Calculator

Compare trapezoidal rule, Simpson's rule and Gauss–Legendre quadrature for any integral, with each method's error.

Also known as: simpson's rule calculator, trapezoid rule calculator, gaussian quadrature, numerical integral.

How to use this calculator

  1. Enter f(x), a, b, intervals n.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

Trapezoid: h/2·[f₀ + 2f₁ + … + fₙ] · Simpson: h/3·[f₀ + 4f₁ + 2f₂ + … + fₙ]

Worked example

Using the values pre-filled in the calculator above:

  • f(x): sqrt(1 + x^3)
  • a = 0
  • b = 2
  • Intervals n = 10

the calculator returns:

  • Best estimate (adaptive): 3.241309263195