Calculus Calculator

Interactive calculus calculator for derivatives, definite integrals, and limits. Enter a single-variable function f(x) and receive numeric estimates with transparent methods.

Use x as the variable. Supported functions include sin, cos, tan, exp, ln, sqrt, abs, powers via ^, and constants pi or e.

Derivative at x₀

Central difference

f′(x₀)

Leave empty for scaling based on x₀; set to a small non-zero value to override.

Definite integral

Composite Simpson’s rule

∫ f(x) dx

Example: π ≈ 3.14159

Higher values add precision at the cost of time.

Limit of f(x)

Samples from left and right

The calculator shrinks h automatically from this seed.

How to use this calculator

Enter a single-variable real function f(x). Use the derivative controls to probe the slope at a point, the integral controls to compute area between limits, and the limit controls to inspect left/right behavior. Click Calculate once you have provided numeric inputs.

What this tool is for

The calculator offers transparent numeric estimates rather than symbolic proofs. It is ideal for learning, sanity-checking analytic work, and quick explorations, but always verify results in exams or graded assignments with your instructor’s allowed methods.

Methodology

Calculus hinges on differentiation (rates of change) and integration (accumulated quantities). This tool implements both numerically so you can see how computers approximate core operations.

Derivative: central difference formula

The derivative at a point is defined as the limit

\[f'(x_0) = \lim_{h \to 0} \frac{f(x_0 + h) - f(x_0 - h)}{2h}.\]

Numerically we use a small finite h for the central difference.

\[f'(x_0) \approx \frac{f(x_0 + h) - f(x_0 - h)}{2h}.\]

The calculator automatically chooses h based on the scale of x₀ unless you override it, and highlights the step size in the results.

Definite integral: Simpson’s rule

Integrals accumulate area between two limits.

\[\int_a^b f(x)\,dx\]

We partition [a, b] into n even subintervals of width \(\Delta x = \frac{b - a}{n}\) and evaluate at the grid points.

\[\int_a^b f(x)\,dx \approx \frac{\Delta x}{3} \left[f(x_0) + f(x_n) + 4 \sum_{k=1,3,\dots}^{n-1} f(x_k) + 2 \sum_{k=2,4,\dots}^{n-2} f(x_k) \right].\]

More subintervals usually mean better accuracy, but the method can still struggle with discontinuities or unbounded features.

Limits: sampling from left and right

The calculator evaluates f(x) at points approaching x₀ from smaller and larger values and averages the stable readings.

\[\lim_{x \to x_0} f(x)\]

If both sides settle to nearly the same value, we report an approximate two-sided limit. If they diverge or disagree significantly, you will see a warning in the summary.

Examples you can try

  • Derivative: \(f(x) = x^3 - 4x + 1\) at \(x_0 = 2\). Analytically \(f'(x) = 3x^2 - 4\), so \(f'(2) = 8\).
  • Integral: \(f(x) = \sin(x)\) from 0 to \(\pi\) returns 2.
  • Limit: \(f(x) = \frac{\sin(x)}{x}\) as \(x \to 0\) equals 1.

FAQ: using the calculus calculator safely

What can I do with this calculus calculator?

You can compute numeric derivatives, definite integrals, and limits with transparent methods for learning and quick checks.

How accurate are the derivative and integral results?

For smooth functions, central differences and Simpson’s rule are accurate; accuracy drops near discontinuities, highly oscillatory functions, or very wide intervals. Adjust h or n and compare with analytic work when precision matters.

Can I use this tool on exams or graded homework?

No. This is for learning and exploration. Always comply with your instructor’s rules and show the analytic work requested.

What function syntax does the calculator support?

Use x as the variable and operators +, -, *, /, ^. Functions: sin(x), cos(x), tan(x), exp(x), ln(x), sqrt(x), abs(x). Constants: pi, e.

Examples: x^2 * exp(-x), sin(x)/x, ln(1 + x), sqrt(1 - x^2) (on \([-1,1]\)).

Author

Ugo Candido creates transparent calculator logic and educational resources for real-world decision-making. Feedback and corrections are welcome.

Contact: info@calcdomain.com

Editorial policy

CalcDomain tools are designed for educational use, reviewed for clarity and accuracy, and built without paid influence on results. Inputs and assumptions are transparent so you can verify every outcome.

Formulas

Derivative definition

\[f'(x_0) = \lim_{h \to 0} \frac{f(x_0 + h) - f(x_0 - h)}{2h}.\]

Numerical derivative

\[f'(x_0) \approx \frac{f(x_0 + h) - f(x_0 - h)}{2h}.\]

Integral

\[\int_a^b f(x)\,dx\]

Simpson’s rule

\[\int_a^b f(x)\,dx \approx \frac{\Delta x}{3} \left[f(x_0) + f(x_n) + 4 \sum_{k=1,3,\dots}^{n-1} f(x_k) + 2 \sum_{k=2,4,\dots}^{n-2} f(x_k) \right].\]

Limit

\[\lim_{x \to x_0} f(x)\]

Variables and units

  • T = property tax (annual or monthly depending on input) (currency)
Citations

NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures

FTC — Consumer advice — consumer.ftc.gov · Accessed 2026-01-19
https://consumer.ftc.gov/

Changelog
  • 0.1.0-draft — 2026-01-19: Initial audit spec draft generated from HTML extraction (review required).
  • Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the calculator methodology.
Verified by Ugo Candido Last Updated: 2026-01-19 Version: 0.1.0-draft
Version 1.5.0