Calculus students memorize dozens of derivative rules, but the power rule does most of the heavy lifting alone. It says the derivative of xⁿ is n times x to the (n−1): d/dx[xⁿ] = n × xⁿ⁻¹. The derivative of x³ is 3x², the derivative of x² is 2x, and the derivative of x itself is 1 — the exponent drops down front and shrinks by one, every single time. Velocity is the derivative of position and acceleration the derivative of velocity, so this one rule unlocks most of first-semester physics.

This calculator performs the rule's multiplication. Type the exponent n into Variable A and the value of xⁿ⁻¹ — x raised to one less than the exponent — into Variable B; the Result box gives the derivative. An engineering sophomore at UT Austin differentiating 4x³, for instance, enters 3 in Variable A and the value of x² in Variable B, then multiplies the Result by 4 for the final 12x². It also runs backward in spirit: seeing n × xⁿ⁻¹ should immediately suggest the original xⁿ, the recognition that makes integration click.

With the pre-filled defaults — Variable A 10, Variable B 5 — the Power Rule Calculator returns Result 50.0000. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.