Partial Derivative Calculator: Simplify It Free in 2 Steps

Partial Derivative Calculator ∂/∂x

Differentiate a multivariable function with respect to one variable, holding the others constant.

Partial derivative
Show working (LaTeX)

Use * for multiply and ^ for powers. Other variables are treated as constants.

This free partial derivative calculator differentiates a multivariable function with respect to one variable while treating the others as constants — shown in clean LaTeX.

How to use the partial derivative calculator

Type your function and the variable to differentiate by, then press Differentiate. The partial derivative calculator holds the other variables constant and returns the simplified partial. As a multivariable derivative calculator and partial differentiation calculator, it handles polynomials, trig, exponentials and more.

partial derivative calculator showing a tangent slope on a multivariable surface
A partial derivative is the slope along one axis, holding the other variables fixed.

What is a partial derivative?

A partial derivative measures how a function changes as one variable changes, with the others held fixed. See the partial derivative reference for the formal definition.

Definition. The partial derivative $\partial f/\partial x$ differentiates $f$ with respect to $x$ while treating every other variable as a constant.

Partial derivative formula

$$\frac{\partial f}{\partial x}=\lim_{h\to0}\frac{f(x+h,y)-f(x,y)}{h}$$

How to take a partial derivative step by step

  1. Pick the variable to differentiate by.
  2. Treat all other variables as constants.
  3. Differentiate as usual with the standard rules.
⚠️ RememberWhen differentiating by x, a term like $y^3$ has no x in it, so its partial derivative is 0 — it is treated as a constant.

Worked example

For $f(x,y)=x^2y+y^3$, the partial with respect to x is $\frac{\partial f}{\partial x}=2xy$, because $y^3$ is constant in x.

Why partial derivatives matter in machine learning

Partial derivatives are the heart of training in machine learning for beginners: the gradient is just the vector of partial derivatives of the loss with respect to each weight. They extend the single-variable derivative and power calculus-based optimization.

🤖 ML insight

Gradient descent updates every weight using its partial derivative of the loss, so the model learns by nudging each parameter in the direction that reduces error.

Frequently asked questions

How do I choose the variable?
Type it in the “With respect to” box (for example x or y).
How are the other variables handled?
They are treated as constants while you differentiate.
Can it do second partial derivatives?
Yes — differentiate the result again with respect to the same or another variable.
What is the gradient?
The vector of all first partial derivatives of a function.
Is the partial derivative calculator free?
Yes, completely free and browser-based.

Gradients and higher partials

Collecting every first partial into a vector gives the gradient, which points in the direction of steepest increase. Differentiating a partial again produces a second-order partial; the mixed partials are equal for smooth functions, a fact known as Clairaut’s theorem.

In practice you rarely compute these by hand for large models. Automatic differentiation libraries apply the chain rule across millions of operations to get every partial efficiently — but understanding what a single one means is what makes the gradient, and gradient descent, click.

Partial derivative calculator: summary

This partial derivative calculator differentiates multivariable functions one variable at a time. Pair it with the derivative calculator and the integral calculator.

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