Math Calculators
85 free online calculators — instant results, no sign-up
All 85 Math Calculators Tools
HOT
Basic Calculator
Add, subtract, multiply, divide with full keyboard supportHOTScientific Calculator
Trig, log, exponent, factorial · DEG/RAD modesHOTPercentage Calculator
Percent of, percentage share, and percent changeFraction Calculator
Add, subtract, multiply, divide fractions with simplificationHOTNumber Base Converter
Convert between binary, octal, decimal and hexadecimalPermutation & Combination Calculator
Permutations A(n,m) and combinations C(n,m)Random Number Generator
Custom range, integers or decimals, batch generationPrime Number Tools
Primality test, prime factorization and prime listsGCD & LCM Calculator
Greatest common divisor and least common multipleNEWSequence Calculator
Arithmetic & geometric sequences, sums and nth termNEWEquation Solver
Linear and quadratic equations with real solutionsNEWSquare Root Calculator
√x — real square roots with precisionNEWCube Root Calculator
∛x — real cube rootsNEWAbsolute Value Calculator
|x| — absolute value of any numberNEWLogarithm Calculator
log, ln and log with any baseNEWExponent Calculator
x^y — any base raised to any powerNEWFactorial Calculator
n! — factorials including large numbersNEWModulo Calculator
a mod b — remainder of divisionStatistics Calculator
Mean, median, mode, variance, standard deviation and quartilesRatio Calculator
Solve A:B=C:D, simplify ratios and allocate proportionallyMatrix Calculator
Determinant, inverse, transpose and matrix multiplicationTriangle Solver
Solve sides and angles (SSS/SAS) with law of cosinesWeighted Average Calculator
Values and weights to weighted mean with normalizationSlope Calculator
Slope, intercept, distance and midpoint from two pointsComplex Number Calculator
Complex arithmetic, modulus, argument and conjugateProbability Calculator
Classical, hypergeometric and at-least-once probabilityTrigonometry Calculator
sin/cos/tan values, inverse trig and special anglesVector Calculator
3D vector add/subtract, dot & cross product, magnitude, angleNormal Distribution Calculator
Z-score, percentile and probability between valuesSystem of Equations Solver
Two-variable linear system solved by Cramer's ruleConfidence Interval Calculator
Mean CI at 90/95/99% with margin of errorMean Median Mode Calculator
Central tendency trio with sorted comparisonPercent Error Calculator
Measured vs true value — experimental errorRounding Calculator
Any precision, round-half-to-even and truncationPercentage Change Calculator
Increase/decrease percent and reverse calculationNth Root Calculator
Any-degree root of any numberQuadratic Equation Solver
Discriminant, real/complex roots and vertexZ-Score Calculator
Standardization, percentile and normal probabilityDistance Between Points Calculator
2D/3D Euclidean and Manhattan distanceSignificant Figures Calculator
Count sig figs, round, apply +−×÷ rulesScientific Notation Converter
a×10^n, engineering notation, E-notationLinear Regression Calculator
Least squares fit, scatter plot, r²Geometric & Harmonic Mean
AM-GM-HM inequality, growth ratesFibonacci Calculator
Nth term with BigInt, golden ratio convergenceModular Exponentiation
Fast power a^b mod m, BigInt, cyclesIQR & Quartile Calculator
Q1/Q2/Q3, IQR, outlier fencesMargin of Error Calculator
Confidence interval & sample sizeBayes Theorem Calculator
Posterior probability, medical screeningExpected Value Calculator
E(X), variance, standard deviationKelly Criterion Calculator
Optimal bet size, half KellyStandard Deviation Calculator
Population/sample SD, variance, CV, SEMDecimal to Fraction Calculator
Repeating decimals + continued fractionsFactoring Calculator
GCF · cross method · perfect squareExponential Growth Calculator
N0(1+r)^t · doubling & half-lifeBinomial Expansion Calculator
(a+b)^n coefficients · Pascal triangleInequality Solver
Linear + quadratic · solution set · stepsLong Division Calculator
Quotient & remainder · step-by-step workCorrelation Calculator
Pearson r · R² · significance t-testPoisson Distribution Calculator
P(X=k) · cumulative · full tableChi-Square Test Calculator
2x2 table · p-value · Yates correctionp-value Calculator
Z / t / chi-square statistic · one & two tailed · starsPercentile Calculator
Percentile rank PR · P25/P50/P75 quantiles · IQRBinomial Distribution Calculator
P(X=k) & cumulative · mean/SD · approximationsCovariance Calculator
Sample & population covariance · Pearson rConfusion Matrix Calculator
Accuracy/precision/recall/F1 · 8 metricsSample Size Calculator
n vs margin of error · finite populationFunction Graph Plotter
Plot any f(x) · zeros & intercepts markedSummation (Σ) Calculator
Sum any expression term by term · partial sums · closed formsMath Worksheet Generator
Printable drills by level · answer key · seed replaySynthetic Division Calculator
Synthetic & long division · remainder theorem · rational rootsWork Together Calculator
Combined work time · head start · fill & drain pipes · back-solveCritical Value Calculator
Z/t/χ² inverse lookup, two or one tail, rejection regionLinear Interpolation Calculator
Interpolate or extrapolate between two points, table lookupPolar Coordinates Calculator
Convert between polar (r, θ) and Cartesian (x, y)Point to Line Distance Calculator
Distance formula, foot of perpendicular and mirror pointAlligation Calculator
Cross method for mixing ratios and weighted averagesMeeting & Chase Calculator
Relative speed problems and circular track lapsData Analysis Calculator
Base period, growth amount, two-period ratio and average growthClock Angle Calculator
Hand angle, overlap time and perpendicular momentsBirthday Paradox Calculator
Shared-birthday probability and people neededGaokao Scaled Score Calculator
3+1+2 elective grade conversion via linear mappingOne-Sample t-Test Calculator
t=(x̄−μ₀)/(s/√n) · t stat, p-value, significanceEffect Size Calculator (Cohen's d)
Cohen's d · pooled SD · small/medium/largeDiagnostic Test Evaluator
Sensitivity / specificity / PPV / NPV / YoudenShannon Entropy Calculator
H=−Σp·log₂p · information content · distribution entropyRelated Guides
Percentage: How to Calculate Shares, Change & Discounts
Three core questions: X% of Y = Y×X÷100; what % is A of B = A÷B×100; percent change = (new−old)÷old×100. Covers discounts, growth rates, percentage points vs percent, and the classic traps that fool most people.
Mean, Median & Mode: When to Use Each
Mean is skewed by outliers (average salary myth); median is the middle value and robust; mode is the most frequent. House prices and salaries should use median. Includes calculation steps, comparison table, and the "average trap" in real-world statistics.
Standard Deviation: Formula, Meaning & Use Cases
Standard deviation measures spread: ~68% of data falls within ±1σ, 95% within ±2σ (normal distribution). Sample version divides by n−1, population by n. Includes step-by-step calculation, CV for comparing volatility, and real uses from quality control to fund risk.
GPA: How to Calculate Grade Point Average
GPA = Σ(grade point × credits) ÷ Σ credits. Standard 4.0 scale: A=4, B=3, C=2, D=1, F=0. A 3-credit A and 4-credit B → (12+12)/7 = 3.43. Covers weighted vs unweighted, Chinese 5.0/4.0 conversions, and what top universities expect.
Target Score: What Do I Need on the Final Exam?
Needed score = (target − current × current weight) ÷ final weight. Current 85 (60% weight), target 90, final worth 40% → need 97.5. Covers weighted grade math, feasibility checks, and how to plan across multiple remaining assessments.
Car On-Road Price: The 6 Fees Beyond the Sticker
On-road price = sticker + purchase tax (10% of net price) + insurance + registration + extras. A ¥150k car lands at ~¥168k. Covers each fee's formula, new-energy exemptions, and the dealer add-ons you can refuse.