Trapezoidal Rule Calculator

The Trapezoidal Rule approximates a definite integral by dividing the area under the curve into trapezoids rather than rectangles. Each trapezoid connects adjacent function values with a straight line

The calculator uses the standard published formula for trapezoidal rule. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

This calculator works with inches. You can enter values in the units shown — the calculator handles all conversions internally.

The core formula is: T = (h/2)[f(x₀) + 2f(x₁) + 2f(x₂) + ... + 2f(xₙ₋₁) + f(xₙ)]. Each step in the calculation is shown so you can verify the result manually.