For a place-value system, the value of a digit results from the position of the digit within the number. The value of the number is determined by the sum of the digits, each digit being multiplied by the digits place value. The place value is the position-dependent power of the base value b of the place value system. The numbers are written as a sequence of digits from left to right, the left is started with the highest place value, and the place value is then reduced to the next position by one (b-adic representation) in the exponent. The transition to negative exponents of the base value is indicated by a ".". The number of different digit symbols required is equal to the base value b.

Structure of a number in the place-value system with the digits a_{n}a_{n-1}... a_{0}.a_{-1}... a_{-m}. The value is calculated according to

$${a}_{n}{b}^{n}+{a}_{\mathrm{n-1}}{b}^{\mathrm{n-1}}+\dots +{a}_{1}{b}^{1}+{a}_{0}{b}^{0}+{a}_{-1}{b}^{-1}+\dots +{a}_{\mathrm{-m}}{b}^{\mathrm{-m}}=\sum _{i=0}^{\mathrm{m+n}}{a}_{\mathrm{i-m}}{b}^{\mathrm{i-m}}$$

Base value b = 10

Digits 0, 1, 2, ..., 9

Example of a decimal number:

$$1265.42=\sum _{i=0}^{6}{a}_{\mathrm{i-2}}{10}^{\mathrm{i-2}}=2\cdot {10}^{-2}+4\cdot {10}^{-1}+5\cdot {10}^{0}+6\cdot {10}^{1}+2\cdot {10}^{2}+1\cdot {10}^{3}=\frac{2}{100}+\frac{4}{10}+5+6\cdot 10+2\cdot 100+1\cdot 1000$$

Base value b = 2

Digits 0, 1

Example of a binary number:

$${101101}_{2}=\sum _{i=0}^{6}{a}_{i}{2}^{i}=1\cdot {2}^{0}+0\cdot {2}^{1}+1\cdot {2}^{2}+1\cdot {2}^{3}+0\cdot {2}^{4}+1\cdot {2}^{5}=1+4+8+32={45}_{10}$$

Base value b = 16

Digits 0, 1, 2, ...,9, A, B, C, D, E, F

Example for a hexadecimal number:

$${\mathrm{10FE1A}}_{16}=\sum _{i=0}^{6}{a}_{i}{16}^{i}=\mathrm{A}\cdot {16}^{0}+1\cdot {16}^{1}+\mathrm{E}\cdot {16}^{2}+\mathrm{F}\cdot {16}^{3}+0\cdot {16}^{4}+1\cdot {16}^{5}=10+16+3584+61440+1048576={1113626}_{\mathrm{10}}$$

Octal system

Base 8

Duo-decimal system

Base 12

Sexagesimal system

Base 60

Base64

Base 64

Radix32

Base 32

Vigesimal system

Base 20

In the number system conversion calculator are digits greater then 9 to be set by letters A, B, C, ...

The starting point of the iteration is the decimal number. The number is divided by the base and the integer part of the division is used for the next iteration. The remainder of the division is the digit for the new base. The iteration is repeated until the remainder is 0.

The calculation of the decimal places is made by multiplication with the base. The number before the decimal point is the next digit. The decimal part is multiplied by the base until the remainder is 0 or the maximum number of desired digits is reached. Here after 10 positions is the calculation aborted.

Here is a list of of further useful calculators:

Index Matrix Determinant Determinant 2x2 Determinant 3x3 Combinatorics