Math
The math calculators cover the calculations people repeat in study, work and daily life: percentages, fractions, powers and roots, basic geometry, and descriptive statistics. Each one solves a standard problem and, where useful, shows the intermediate values so you can follow the method.
These are descriptive tools — they summarize or evaluate what you give them. For hypothesis tests, confidence intervals and sampling uncertainty, the science category is the better fit.
Browse math calculators
Numbers & arithmetic
Descriptive statistics
Which math calculator do you need?
Take a percentage of a number, or express one number as a percentage of another.
Add, subtract, multiply or simplify fractions without converting to decimals first.
Measure the percentage change between two values, such as a price before and after.
Evaluate roots, powers and logarithms, including negative and fractional exponents.
Evaluate a longer expression that mixes functions, powers and parentheses.
Find the area of a common shape, a missing side of a right triangle, or the slope of a line.
Summarize a data set with a typical value and a measure of how spread out it is.
Percentages and relative change
A percentage always has a base, and most percentage mistakes come from the wrong base. A 20% discount and a 20% markup do not cancel each other, because one is calculated on the original price and the other on the cost.
Percentage points and percent change are also different: moving from 10% to 12% is a rise of two percentage points but a 20% relative increase. Decide which one the question is asking for before reaching for the calculator.
Geometry and descriptive statistics
Area formulas assume consistent units: convert mixed measurements to one unit before multiplying. The Pythagorean theorem applies only to right triangles, and slope is simply rise over run for a straight line.
The mean is sensitive to extreme values while the median is not; when they diverge, the data is skewed. Standard deviation adds the spread around the mean, which is why a mean without it can describe two very different data sets equally well.
Common sources of wrong answers
- Mixing units before calculating is the most frequent error — convert first, then compute.
- Rounding intermediate steps shifts the final result; keep extra digits and round once at the end.
- Descriptive statistics summarize the sample in front of you and say nothing by themselves about a wider population.