Mathematics · Calculus
Simpson's Rule Calculator
Approximate an integral from endpoint and midpoint function values.
Inputs and results stay in this browser. Change one value at a time to explore the relationship.
Calculation steps
- Weighted sum=0+4×1+4=8.
- Estimate=(2−0)×8÷6=2.6666666666666665.
Problem → model → reason → result
What problem does this model solve?
Approximate an integral from endpoint and midpoint function values.
Why does the model apply?
A quadratic through three equally spaced samples integrates to Simpson's weighted formula.
What assumptions does it make?
The function follows the displayed form and is differentiable at the evaluation point. The local rate produced by a derivative is not automatically an average rate over an interval.
Formula
area≈(b−a)[f(a)+4f(mid)+f(b)]/6
Calculation and working
The calculator above substitutes your inputs into the model and leaves the calculation steps visible so the answer can be checked rather than merely accepted.
What does the result mean?
The result answers the stated problem in the units implied by your inputs. Read its sign, size and units together, then compare it with the original values before drawing a conclusion.
Worked example
For x² on 0 to 2, values 0,1,4 give the exact integral 8/3.
Common mistake
The middle value must be evaluated at the interval midpoint.
When does this model not apply?
This compact symbolic model covers the displayed function family, not every function, discontinuity or domain restriction.
How to learn with this calculator
Begin with the worked example, then change one value while keeping the others fixed. Compare the new result and calculation steps to identify which part of the formula changed.
Clear answers
Frequently asked questions
What does the Simpson's rule do?
Approximate an integral from endpoint and midpoint function values.
How does the Simpson's rule work?
The calculator applies area≈(b−a)[f(a)+4f(mid)+f(b)]/6. A quadratic through three equally spaced samples integrates to Simpson's weighted formula.
What can I learn from the Simpson's rule?
It connects the mathematical rule to your chosen numbers and shows each calculation step. Change one input at a time to see how the result responds.
Does MW SysArc receive or store what I enter?
No. The calculation runs locally in your browser. MW SysArc does not receive or store your calculation inputs.
How should I use the result?
Use the steps to understand the method, then verify important school or professional work using the notation and rounding rules required in your setting.
Last reviewed 2026-07-14. Calculations tested 2026-07-14.