Numbers & words

1. 01Choose at the top: In words (write out an amount), Roman (convert both ways) or Number systems (decimal, binary, octal, hex and a system of your own).
2. 02Type a number, the result appears right away. In “Number systems” the field you typed in last leads, the other four follow.
3. 03The address remembers the tab, for example bnkz.de/en/calculator/numbers-in-words/#systeme.

In words. Numbers up to 999,999,999,999,999 (one quadrillion minus one), with decimals and with a minus sign. “As a number” reads the decimals one by one (“point five six”), “Amount” reads them as euros and cents. More than two decimal places cannot be said to the cent, then the amount rows stay empty. The words follow American usage (one hundred five, billion = 1,000,000,000). The switch British “and” adds “and” after the hundreds and before a last group under 100: one hundred and five, one thousand and five. “Amount, check style” writes the cents as a fraction, as on a check: “one hundred and 50/100 euros”. The amount is always in euros.

Roman. Numbers from 1 to 3999, following the usual rule: symbols go from large to small, at most three identical ones in a row, and only I before V or X, X before L or C, C before D or M may subtract. Anything else (IIII, VX, IC and the like) is rejected with the reason, which the rule below explains.

Number systems. Decimal, binary, octal, hexadecimal and a system of your choice from 2 to 36. Whole numbers can be any size, also with a sign. Fractions are written with a point and go up to 20 digits after the point; if a sequence of digits repeats, a note below shows it as a period, otherwise it stops after 20 digits, even if the fraction actually goes on. Two’s complement shows how negative numbers are stored in a fixed bit width, and tells you when a number does not fit.