Math and Statistics

Math and Statistics calculators cover the numbers you meet in school, work, and research — averages and percentages, square roots, standard deviation and normal distributions, number-base conversions, and more. Frequently used tools include the Average Calculator, Percentage Deviation Calculator, Square Root Calculator, Normal Distribution Calculator, and 2's Complement Calculator.

Pick a tool below to get an instant answer, or open the Trending tab to see what other people are calculating this week. Everything is free and works on any device.

  • Age Multiples Word Problem Calculator
    Solve the classic age word problem: a parent is n times the child's age now and m times after some years. Instantly find both current ages.
  • Z Critical Value Calculator
    Find the z critical value for any significance level α. Supports one-tailed (zα) and two-tailed (±zα/2) tests using the inverse normal distribution.
  • Percentage Growth Calculator
    Enter initial and final values to calculate percent change using (final - initial)/initial * 100 and see how much it increased or decreased.
  • Absolute Value Graph Vertex Calculator
    Free combination (nCr) calculator. Find how many ways to choose r items from n where order does not matter, using C(n,r) = n!/(r!(n-r)!).
  • Function End Behavior Calculator
    Convert a line from slope-intercept form y = mx + b into standard form Ax + By = C instantly. Enter slope and y-intercept to get A, B, and C.
  • Rationalize the Numerator Calculator
    Find the distance between two points (x₁,y₁) and (x₂,y₂) using the distance formula d = √((x₂−x₁)² + (y₂−y₁)²). Fast and exact.
  • Negative Binomial Mean and Variance Calculator
    Calculate the interquartile range (IQR = Q3 − Q1) from your data set. Get Q1, median, Q3, IQR and outlier fences instantly with this free IQR calculator.
  • Add and Subtract Rational Expressions Calculator
    Add or subtract two fractions a/b ± c/d, get the combined fraction, simplify it by the greatest common factor, and see the decimal value instantly.
  • Decimal to Fraction Calculator
    Enter a decimal number and instantly see the rounded value. Clean up decimals for easier reading or quick use in your calculations.
  • Chi-Squared Distribution Graph Calculator
    Compute the chi-squared (chi^2) probability density f, lower cumulative P, and upper cumulative Q for any x and degrees of freedom, plus a series for graphing.
  • WAIS-Style IQ Score Calculator (Deviation IQ, Mean 100 · SD 15)
    Convert a raw test score into a deviation IQ score using IQ = 100 + 15(x − μ)/σ. Get your z-score, percentile, and classification instantly.
  • 45-Degree Rule Rise Over Run Calculator
    Calculate slope from rise over run instantly. Get the slope ratio, grade percentage, and angle of incline in degrees for any roof, ramp, or line.
  • Trig Identity Verifier Calculator — Pythagorean Identity (sin²θ + cos²θ = 1)
    Verify sin²θ + cos²θ = 1 and find cos θ from sin θ using cos θ = ±√(1−sin²θ). Pick the quadrant to choose the correct sign.
  • Gaussian Percentile Rank & Upper-Tail Probability Calculator
    Compute P(Z > z) = 1 − Φ(z), the upper-tail probability of the standard normal distribution, plus the cumulative probability and percentile rank for any z-score.
  • Zeros of a Function Calculator — Quadratic & Linear f(x)
    Find the zeros (roots) of a quadratic function f(x)=ax²+bx+c. Solves f(x)=0 with the quadratic formula and reports real or complex roots.
  • Two-Thirds (2/3) as a Percentage Calculator
    Convert any fraction or part-out-of-number into a percentage instantly. Enter numerator and denominator to get the percent and decimal value.
  • Percentage Calculator
    Calculate percentages easily with this Percentage Calculator. Input numbers and select from options like percentage of a number, number as a percentage of another, or percentage change between two numbers for quick results.
  • Percent Error Calculator
    Enter a measured value and a true value to compute percent error, plus absolute and relative error, so you can assess measurement accuracy fast.
  • Percentage Increase Calculator
    Find the percent increase between two numbers in seconds. Enter the original and new value to get the exact growth percentage with the formula. Try it free.
  • Proportion Calculator
    Enter any three of A, B, C, and D to complete A:B = C:D and instantly calculate the missing term. Fast, accurate proportion results.
  • Z Score Calculator
    Calculate the z score (standard score) of a value from the mean and standard deviation using z = (x − μ) / σ. Free, instant, and accurate.
  • Scientific Notation Calculator
    Convert any number to scientific notation (m × 10^e) instantly. Get the mantissa and exponent for very large or very small numbers.
  • Fraction to Percent Calculator
    Convert any fraction into a percentage instantly. Enter the numerator and denominator to get the exact percent and decimal equivalent.
  • Absolute Value Calculator
    Find the absolute value of any number instantly. Enter a positive, negative, or decimal value and get |x| with a clear worked explanation.

Frequently asked questions

What can I calculate with these math and statistics tools?

Everyday and academic math: means, medians and other averages, percentages and percent change, powers and roots, standard deviation and variance, probability and distributions, and base conversions such as binary or two's complement.

Do the calculators show the steps or formula?

Most show the formula and the worked result so you can follow the method, not just the final number — useful for checking homework or understanding the calculation.

Are they free and do they work on mobile?

Yes to both — free, no sign-up, and fully responsive on phones and tablets.

How accurate are the results?

They use standard mathematical formulas and are tested against known values. For high-precision or academic work, verify rounding and significant figures against your own requirements.

Which math calculators are most popular?

The list is ordered by how often each tool is used, so the most popular appear first. The Trending, Recently added, and Last updated tabs highlight what's new and rising.

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