Everyday & Math
The quick math you reach for constantly — percentages, tips, discounts, sales tax, averages, ratios, GPA — each one a transparent formula with a worked example you can check, not a black box. Built to give the right answer in seconds and show you exactly how it got there.
- Everyday & MathLivePercentage CalculatorWork out what X% of a number is, what percentage one number is of another, or the percent change between two values. Three modes, one calculator.
- Everyday & MathLivePercentage Change CalculatorMeasure the percentage increase or decrease from an old value to a new one. Shows the signed percent change and the raw difference between the two figures.
- Everyday & MathLiveTip CalculatorWork out the tip, the grand total, and each person's share. Enter the bill, the tip percentage, and how many people are splitting it.
- Everyday & MathLiveDiscount CalculatorFind the sale price after a percentage off, and see exactly how much you save. Enter the original price and the discount percent.
- Everyday & MathLiveSales Tax CalculatorAdd sales tax to a subtotal and see the tax amount and grand total. Enter the pre-tax price and your local sales-tax rate.
- Everyday & MathLiveRatio CalculatorReduce a ratio like 12:8 to its simplest form and solve a proportion for a missing term. Enter two ratio terms and one known value.
- Everyday & MathLiveFraction CalculatorAdd, subtract, multiply, or divide two fractions and get the answer reduced to its simplest form. Enter each numerator and denominator.
- Everyday & MathLiveAverage CalculatorFind the average (arithmetic mean) of up to six numbers. Enter your values and see the mean, the count, and the total.
- Everyday & MathLiveStandard Deviation CalculatorFind the standard deviation of a data set — both the sample (n−1) and population (n) versions — plus the mean. Enter up to eight numbers.
- Everyday & MathLiveLCM and GCD CalculatorFind the greatest common divisor (GCD) and least common multiple (LCM) of two whole numbers using Euclid's algorithm. Enter two integers.
- Everyday & MathLiveCross-Multiply CalculatorSolve a/b = c/x for the missing value by cross-multiplying. Enter the three known numbers and get the fourth — the classic rule of three.
- Everyday & MathLiveGPA CalculatorCalculate your weighted GPA on a 4.0 scale from your course grades and credit hours. Enter each course's grade points and credits.
- Everyday & MathLiveGrade CalculatorCombine assignment, quiz, and exam scores by their weights into one overall course grade and letter. Enter each score and its weight.
- Everyday & MathLiveMarkup and Margin CalculatorTurn a cost and a selling price into markup percentage, margin percentage, and profit. See why markup and margin differ for the same sale.
- Everyday & MathLiveScientific Notation ConverterConvert a plain decimal number into normalised scientific notation (a × 10^n), with a coefficient between 1 and 10 and the power of ten.
- Everyday & MathLiveSquare Footage CalculatorFind the area of a rectangular room or space from its length and width, in square feet and square yards. Pure area arithmetic.