Numerical integration approximates the area represented by a definite integral when an analytic antiderivative is unavailable or sampled values are used. Trapezoidal and Simpson rules combine function evaluations differently, with accuracy depending on interval spacing, smoothness, and resolution.
Numerical Integration Calculator applies this concept to its defined inputs and workflow. It estimates area under a curve using composite quadrature rules for expressions or trapezoidal integration for supplied x-y tables.
The calculator evaluates safe expression and x-y table and returns integral estimate, sample table, and function visual using the stated method. The selected units and sign or reference conventions must describe one consistent physical case. Users should interpret the output within the assumptions shown on the page and repeat the check with trusted reference values when the result affects engineering or research decisions. Adaptive quadrature is not included.