• Sales Tax Backed Out of Total Calculator
    Back out the sales tax from a tax-inclusive total. Enter the gross amount and tax rate to find the net price and the tax included.
  • X-Intercept Calculator
    Find the x-intercept of a line from its slope-intercept equation y = mx + b. Set y = 0 and solve x = −b/m with worked steps.
  • Factor Out the GCF from a Polynomial Calculator
    Factor out the greatest common factor (GCF) from any polynomial. Enter the terms and get the fully factored form with steps. Free and instant.
  • Percent Grade to Degrees Calculator
    Convert a percent grade (slope) into degrees instantly. Enter the grade % to get the slope angle in degrees and radians using arctangent.
  • Target Heart Rate Zone Percentage Calculator
    Calculate your target heart rate at any exercise intensity percentage using your age and the 220-minus-age maximum heart rate formula.
  • Alcohol Proof to Percentage (ABV) Calculator
    Convert US alcohol proof to percentage alcohol by volume (ABV) instantly. Just divide proof by 2 — enter the proof to get the exact ABV percentage.
  • Stock Price Percent Gain/Loss Calculator
    Calculate the percentage gain or loss on a stock from its buy and sell price. Get profit per share and total profit instantly. Free and universal.
  • 15 Percent Tip Calculator
    Calculate a 15% tip and total bill instantly. Enter your bill amount, optionally split between people, and see the tip and total per person.
  • Fraction Out of Number to 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.
  • 20 Percent Off Calculator
    Calculate 20% off any price instantly. Enter the original price to see the sale price and how much money you save with a 20 percent discount.
  • 50% Off Calculator
    Calculate 50 percent off any price instantly. Enter the original price to see the half-off sale price and how much money you save.
  • 30 Percent Off Calculator
    Calculate 30% off any price instantly. Enter the original price to see the discounted sale price and the exact amount you save.
  • Win Rate Calculator
    Calculate your win rate percentage from wins and games played. Free win rate calculator for esports, sports, gaming and matches with instant results.
  • 3D Vector Cross Product Calculator
    Compute the cross product of two 3D vectors a × b instantly. Get each component (x, y, z) plus the magnitude of the resulting perpendicular vector.
  • Number Base Converter Calculator
    Convert numbers between binary, octal, decimal, and hexadecimal. Free base converter using place value and repeated division with worked steps.
  • De Moivre's Theorem Calculator
    Apply De Moivre's theorem to raise a complex number in polar form (r∠θ) to a power n. Get modulus, angle, and rectangular a+bi form instantly.
  • Perpendicular Line Through a Point Calculator
    Find the equation of the line perpendicular to a given slope and passing through a point. Computes perpendicular slope (-1/m) and y-intercept instantly.
  • Grade Percentage Needed Calculator
    Find the average score you need on the remaining work to hit your target final grade, based on your current grade and weight completed.
  • Function Operations Calculator
    Combine two function values with addition, subtraction, multiplication, or division: (f+g)(x), (f−g)(x), (f·g)(x), and (f/g)(x). Free and instant.
  • Arithmetic Sequence Calculator
    Compute the nth term (aₙ) and the sum (Sₙ) of an arithmetic sequence from the first term, common difference, and term position.
  • Percentage of Max Heart Rate Calculator
    Calculate your target heart rate from a percentage of your estimated maximum heart rate using your age. Find training zones in beats per minute fast.
  • Original Value Before Percent Change Calculator
    Find the original value before a percent increase or decrease. Enter the final value and percent change to reverse-calculate the starting amount instantly.
  • Percent Markup on Cost Calculator
    Calculate percent markup on cost from your item cost and selling price. Instantly see markup %, profit per unit, and profit margin.
  • How Much Percent Decrease Calculator
    Find out how much percent a value decreased. Enter the original and new value to instantly calculate the percentage decrease and absolute change.