GetPercentConvert
    Reference Guide

    Math Glossary

    Clear, simple definitions for every percentage-related term you'll encounter.

    A

    Absolute value

    The non-negative value of a number, ignoring its sign. In percentage calculations, we use it to find the size of a change regardless of whether it's positive or negative.

    Example:|−5| = 5

    Average

    The sum of values divided by the count. In percentage difference calculations, the average of two numbers is used as the reference point (the denominator).

    Example:(10 + 20) / 2 = 15
    B

    Baseline

    The original or starting value used as the reference point in a calculation. In percent change, the 'From' value is the baseline.

    Example:If price went from $100 to $120, $100 is the baseline.
    D

    Decimal

    A number expressed in base-10 notation. Percentages can be converted to decimals by dividing by 100.

    Example:75% = 0.75

    Denominator

    The bottom number in a fraction; represents the whole or the total number of parts.

    Example:In 3/4, 4 is the denominator.
    E

    Error (measurement)

    The difference between a measured (experimental) value and the true (theoretical) value.

    Example:Measuring 9.8 when it should be 10.0 gives an error of 0.2.

    Experimental value

    The value obtained from a measurement, experiment, or observation in the real world.

    Example:A student measuring gravity as 9.5 m/s².
    F

    Fraction

    A way to express a ratio of two numbers, written as a numerator over a denominator.

    Example:1/2 is a fraction equal to 50%.
    N

    Numerator

    The top number in a fraction; represents the part being considered.

    Example:In 3/4, 3 is the numerator.
    P

    Percent

    From the Latin 'per centum' meaning 'per hundred'; a ratio where the whole is always 100.

    Example:20% means 20 for every 100.

    Percentage

    A number or ratio expressed as a fraction of 100, usually denoted with the % symbol.

    Example:Sales tax is often a percentage of the purchase price.

    Percentage change

    The relative change between an old value and a new value, expressed as a percentage of the old value.

    Example:A stock rising from $10 to $11 is a 10% change.

    Percentage difference

    The absolute difference between two similar values, expressed as a percentage of their average.

    Example:Comparing a $50 shoes to $60 shoes.

    Percentage error

    The difference between an experimental and theoretical value, expressed as a percentage of the theoretical value.

    Example:Used in science to check the accuracy of results.

    Percentage increase

    The growth from one value to another, expressed as a percentage of the starting value.

    Example:A 5% pay raise on $50,000.

    Percentage point

    A unit for the arithmetic difference between two percentages. Not the same as percent change.

    Example:Moving from 10% to 15% is a 5 percentage point increase (but a 50% increase).

    Proportion

    A statement that two ratios or fractions are equal.

    Example:1/2 = 50/100
    R

    Rate

    A ratio that compares two quantities with different units, often expressed as a percentage over time.

    Example:Interest rate of 4% per year.

    Ratio

    A comparison of two quantities by division, often written as a:b or a/b.

    Example:A ratio of 1:4 is the same as 25%.

    Reverse percentage

    The process of finding the original whole amount when only the part and the percentage are known.

    Example:If $20 is 10%, the whole is $200.
    T

    Theoretical value

    The expected, accepted, or 'correct' value in a calculation or scientific experiment.

    Example:The speed of light is a theoretical value.
    W

    Whole

    The total or complete amount; the baseline reference that represents 100%.

    Example:In '20% of 150', 150 is the whole.

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