Math calculators

The Percentage Calculator answers “what is X% of Y?” by multiplying the base number by X divided by 100. It accepts decimal and negative percentages, so it can also illustrate a signed change or adjustment.

This is an amount-of-a-base calculation. To compare two values as a percentage change, you must first choose a starting value and a final value; that is a different question. The worked example and formula on the tool page show which number plays each role.

Percentage Increase computes signed change from a positive baseline, while Discount subtracts one percentage from an original price. Fraction performs exact rational arithmetic; Ratio simplifies a two-part proportion, divides a total and solves a matching side. Average handles a list of equally weighted observations and shows the median for context. Each page uses different inputs because the mathematical question is different.

Scientific evaluates a limited real-number expression grammar with an explicit angle mode. Use it for trig, logarithms and powers; use the focused Percentage or Fraction pages when their distinct result explanations are needed.

Equation Solver instead accepts a, b and c for ax²+bx+c=0, classifies linear and constant cases, and applies the quadratic discriminant for real roots. Scientific evaluates an expression but does not automatically solve for an unknown variable.

Area and Volume calculates dimensions of four geometric shapes; choose it to multiply measured lengths into square or cubic units. The Area and Volume unit converters instead translate an already known area or volume between units.