Orders of magnitude (numbers)
This list contains selected positive numbers in increasing order, including counts of things, dimensionless quantities and probabilities.
Each number is given a name in the short scale, which is used in English-speaking countries, as well as a name in the long scale, which is used in some of the countries that do not have English as their national language.
(0.000000000000000000000000000001; 1000−10; short scale: one nonillionth; long scale: one quintillionth) ISO: quecto- (q) (0.000000000000000000000000001; 1000−9; short scale: one octillionth; long scale: one quadrilliardth) ISO: ronto- (r) (0.000000000000000000000001; 1000−8; short scale: one septillionth; long scale: one quadrillionth) ISO: yocto- (y) (0.000000000000000000001; 1000−7; short scale: one sextillionth; long scale: one trilliardth) ISO: zepto- (z) (0.000000000000000001; 1000−6; short scale: one quintillionth; long scale: one trillionth) ISO: atto- (a) (0.000000000000001; 1000−5; short scale: one quadrillionth; long scale: one billiardth) ISO: femto- (f) (0.000000000001; 1000−4; short scale: one trillionth; long scale: one billionth) ISO: pico- (p) (0.000000001; 1000−3; short scale: one billionth; long scale: one milliardth) ISO: nano- (n) (0.000001; 1000−2; long and short scales: one millionth) ISO: micro- (μ) (0.001; 1000−1; one thousandth) ISO: milli- (m) (0.01; one hundredth) ISO: centi- (c) (0.1; one tenth) ISO: deci- (d) (1; one) (10; ten) ISO: deca- (da) (100; hundred) ISO: hecto- (h) (1000; thousand) ISO: kilo- (k) (10000; ten thousand or a myriad) (100000; one hundred thousand or a lakh).
(1000000; 10002; long and short scales: one million) ISO: mega- (M) (10000000; a crore; long and short scales: ten million) (100000000; long and short scales: one hundred million) (1000000000; 10003; short scale: one billion; long scale: one thousand million, or one milliard) ISO: giga- (G) (10000000000; short scale: ten billion; long scale: ten thousand million, or ten milliard) (100000000000; short scale: one hundred billion; long scale: hundred thousand million, or hundred milliard) (1000000000000; 10004; short scale: one trillion; long scale: one billion) ISO: tera- (T) (1000000000000000; 10005; short scale: one quadrillion; long scale: one thousand billion, or one billiard) ISO: peta- (P) (1000000000000000000; 10006; short scale: one quintillion; long scale: one trillion) ISO: exa- (E) (1000000000000000000000; 10007; short scale: one sextillion; long scale: one thousand trillion, or one trilliard) ISO: zetta- (Z) (1000000000000000000000000; 10008; short scale: one septillion; long scale: one quadrillion) ISO: yotta- (Y) (1000000000000000000000000000; 10009; short scale: one octillion; long scale: one thousand quadrillion, or one quadrilliard) ISO: ronna- (R) (1000000000000000000000000000000; 100010; short scale: one nonillion; long scale: one quintillion) ISO: quetta- (Q) (1000000000000000000000000000000000; 100011; short scale: one decillion; long scale: one thousand quintillion, or one quintilliard) (1000000000000000000000000000000000000; 100012; short scale: one undecillion; long scale: one sextillion) (1000000000000000000000000000000000000000; 100013; short scale: one duodecillion; long scale: one thousand sextillion, or one sextilliard) (1000000000000000000000000000000000000000000; 100014; short scale: one tredecillion; long scale: one septillion) (10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000; short scale: ten duotrigintillion; long scale: ten thousand sexdecillion, or ten sexdecillard)[72] (One googolplex; 10googol; short scale: googolplex; long scale: googolplex)
