Everyday Math tools

Percentages, ratios, tips and the small calculations that come up constantly and are easy to get wrong in your head.

• Percentage Calculator - Work out what X% of Y is, what percentage one number is of another, and percentage increase or decrease. Four calculators, instant answers, worked formulas.
• Fraction Calculator - Add, subtract, multiply and divide fractions with results reduced automatically, plus conversion between decimals, fractions and mixed numbers.
• Ratio Calculator - Solve a proportion for a missing value, simplify a ratio to lowest terms, or scale a recipe or mixture up and down while keeping the parts in balance.
• GPA Calculator - Calculate grade point average weighted by credit hours, on the 4.0 scale. Add your courses, see the GPA, and work out what you need next term.
• Tip Calculator - Calculate a tip at any percentage, split the total between any number of people, and round the per-person amount up or down to something payable.
• Discount Calculator - Find the sale price after one or more discounts, see how much you save, and work backwards from a sale price to the discount percentage.
• Aspect Ratio Calculator - Lock an aspect ratio and get the matching width or height. Includes 16:9, 4:3, 1:1, 21:9 and the common social and video presets.