How to Pick the Right Calculator
Start from the problem in front of you. Everyday arithmetic — the basic calculator above
handles it; step up to the scientific calculator
for powers, roots, and trigonometry, and the
percentage calculator for discounts, tips, and
percent change. Fractions and whole numbers — the
fraction calculator adds, simplifies, and converts;
the least common multiple and
greatest common factor calculators find common ground
between numbers, and the factor calculator breaks a
number down completely. Algebra — solve equations with the
quadratic formula calculator, and work
powers and roots with the exponent,
log, and
root calculators.
Statistics — summarize a data set with
statistics or
mean, median, mode, range, measure
spread with standard deviation, and go
further with the z-score,
confidence interval, and
probability calculators.
Geometry — the triangle calculator
solves any triangle from partial information, backed by the
Pythagorean theorem and
right triangle calculators, while
area,
volume, and
surface area cover shapes in two and three
dimensions. Other bases and big numbers — convert and compute with the
binary and
hex calculators, and use
scientific notation and the
big number calculator when ordinary calculators
run out of digits.
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A note on accuracy
Math leaves less room for approximation than most subjects, so these tools are built to be exact
where exactness exists: factors, greatest common factors, and least common multiples are computed
with integer arithmetic and are never rounded. Decimal results are computed in double precision and
shown to 12 significant digits — enough to expose a repeating decimal for what it is instead of
hiding it. Statistics and geometry use the standard textbook formulas (sample vs. population
standard deviation is always labeled, so you know which one you are getting), and every calculator
is checked against reference examples before it is released.
FAQ
Are these calculators free?
Yes — no sign-up, and everything runs in your browser. Nothing you type is sent to a server.
What can the basic calculator on this page do?
Everyday arithmetic with a running expression display, memory keys (M+, M-, MR), an Ans key for the last answer, EXP for entering scientific notation, and RND for a random decimal. For powers, roots, trigonometry, and logarithms, open the Scientific Calculator.
How accurate are the results?
The integer tools — factors, greatest common factor, least common multiple — are exact. Decimal results are computed in double precision and displayed to 12 significant digits, and the statistics and geometry tools use the standard textbook formulas, each checked against reference examples before release.