• Digital Root & Digit Sum Calculator
    Find the digit sum and digital root of any whole number instantly. Uses digital root = 1 + (n-1) mod 9 and adds all base-10 digits.
  • Sum of First n Cubes Calculator
    Compute the sum of the first n cubes (1³+2³+...+n³) instantly using the closed-form identity (n(n+1)/2)². Fast, exact, with worked steps.
  • Collatz Conjecture (3n+1) Calculator
    Compute the Collatz (3n+1) sequence for any positive integer. Find total steps to reach 1 and the highest value reached along the way.
  • Sum of First n Terms of a Geometric Sequence Calculator
    Calculate the sum of the first n terms of a geometric sequence from the first term, common ratio, and number of terms. Free, fast, and accurate.
  • Solve b^x = a for x Calculator
    Solve the exponential equation b^x = a for the unknown exponent x using logarithms: x = ln(a)/ln(b) = log base b of a. Free instant calculator.
  • Equations with Variables on Both Sides Calculator
    Solve linear equations of the form ax + b = cx + d. Enter the coefficients and constants to find x instantly, including no-solution and identity cases.
  • Density, Mass and Volume Solver
    Solve the density formula ρ = m/V for density, mass or volume. Enter any two values and instantly get the third with this free physics calculator.
  • Complete Factored Form of a Quadratic Calculator
    Convert any quadratic ax²+bx+c into complete factored form a(x−r₁)(x−r₂). Solves for real or complex roots using the quadratic formula instantly.
  • Sum of a List of Numbers Calculator
    Add up any list of numbers instantly. Paste comma, space, or newline separated values to get the sum, count, mean, minimum, and maximum.
  • Number to Complete the Square Calculator
    Find the number to complete the square for x² + bx. Enter b and instantly get (b/2)², the constant that turns it into a perfect square trinomial.
  • Variance & Standard Deviation Calculator
    Compute population and sample variance plus standard deviation from a list of numbers. Shows mean, sum of squares, and step-by-step results.
  • Base Conversion Calculator
    Convert numbers between binary, octal, decimal and hexadecimal. Enter any value, pick the source and target base, and get the result instantly.
  • Evaluate an Expression by Substitution Calculator
    Substitute variable values into the expression a·x + b·y + c and simplify instantly. See each term and the final evaluated result step by step.
  • Compare Fractions Calculator
    Compare two fractions instantly using cross multiplication. See which fraction is greater, smaller, or equal plus decimal values.
  • Slope from Rise over Run Calculator
    Calculate the slope (m) of a line from rise over run. Enter vertical rise and horizontal run to get slope, percent grade, and angle of incline.
  • Y-Intercept Calculator
    Find the y-intercept of a line from its equation. Works for slope-intercept (y = mx + b) and standard form (Ax + By = C). Free and instant.
  • Percent Off Calculator
    Find the discount percentage from an original price and a sale price. Instantly see the percent off and the amount you saved.
  • Percentile of a Data Set Calculator
    Find the kth percentile of any data set using linear interpolation. Enter your numbers and a percentile (0–100) to get the exact percentile value.
  • Percent Proportion Solver for X
    Solve the percent proportion part/whole = percent/100 for any unknown. Find the part, the whole, or the percent instantly with steps.
  • Ohm's Law Solver (V = IR)
    Solve Ohm's Law (V = IR) for voltage, current, or resistance. Enter any two values to instantly find the third, plus power dissipation.
  • Adding and Subtracting Polynomials Calculator
    Add or subtract two polynomials instantly. Enter expressions like 3x^2 + 2x - 5, choose + or -, and get the simplified result with like terms combined.
  • Function Transformation Calculator
    Apply shifts, stretches, and reflections to a function using g(x)=a·f(b(x−h))+k. Enter a, b, h, k and evaluate the transformed value at any x.
  • Markup Calculator
    Free markup calculator: enter cost and markup percentage to find selling price, profit, and profit margin instantly. Simple cost-to-price formula.
  • Multiply & Divide Fractions Calculator
    Multiply or divide two fractions and get the answer as a fully reduced fraction plus its decimal value. Free, instant, step-by-step formula included.