Integral Calculator (Definite & Antiderivative)
Compute definite integrals of any function numerically to high precision, and get the exact antiderivative of polynomials — the area under a curve in seconds.
How to use
- 1Type a function of x, e.g. x^2, sin(x) or exp(-x^2).
- 2Enter the lower and upper limits for a definite integral.
How it's calculated
Definite integrals use adaptive Simpson's rule (error target 10⁻¹⁰). For polynomials the antiderivative is exact: ∫ xⁿ dx = xⁿ⁺¹ / (n+1) + C.
Frequently asked questions
Can it integrate trig and exponential functions?
Yes — definite integrals work for any function that's finite on the interval. The symbolic antiderivative is shown for polynomials.
What about improper integrals?
Infinite limits or asymptotes inside the interval aren't supported — use a large finite bound as an approximation.
Why is the answer negative?
A definite integral counts area below the x-axis as negative. The 'total area' output counts all area as positive.