140 tools

Number systems and numerals

140 free number systems and numerals tools, all running in your browser with no sign-up.

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Binary to decimal converterConvert any binary number to decimal with a step table of powers of 2. Handles very long numbers and binary fractions such as 101.101.
Decimal to binary converterConvert decimal numbers to binary with the divide-by-2 table and fraction steps. Spots repeating fractions such as 0.1 and supports huge integers.
Binary to hex converterConvert binary to hexadecimal by splitting the bits into 4-bit groups, with a table showing each group. Accepts fractions and very long bit strings.
Hex to binary converterConvert hex to binary with a table of the four bits behind each digit. Accepts the 0x prefix, lower case letters, fractions and long values.
Binary to octal converterConvert binary to octal by splitting the bits into groups of 3, with a table for each group. Supports binary fractions and long bit strings.
Octal to binary converterConvert octal to binary with a table of the three bits behind each digit. Handy for reading file permissions such as 755 and 644.
Decimal to hex converterConvert decimal to hexadecimal with the divide-by-16 table and fraction steps. Supports huge values such as 64-bit numbers and repeating fractions.
Hex to decimal converterConvert hex values to decimal with a table multiplying each digit by its power of 16. Accepts 0x, lower case, fractions and long values without precision loss.
Decimal to octal converterConvert decimal numbers to octal with the divide-by-8 table and fraction steps. Supports large and negative values and repeating fractions.
Octal to decimal converterConvert octal numbers to decimal with a table multiplying each digit by its power of 8. Accepts the 0o prefix, octal fractions and long numbers.
Octal to hex converterConvert octal to hexadecimal through binary, with the middle step shown. Supports octal fractions and long numbers with full precision.
Hex to octal converterConvert hex to octal through binary with the middle bits shown. Accepts the 0x prefix, lower case letters and hex fractions.
Decimal to BCD converterTurn each decimal digit into 4 bits in standard 8421 BCD, Excess-3 or 2421 code, with a table for every digit and the total bit count.
BCD to decimal converterDecode BCD back to decimal digits, 4 bits at a time, in 8421, Excess-3 or 2421 code, with a clear warning when a group of bits is not valid.
Binary to Gray code converterConvert any binary number to Gray code of the same width by XOR of each bit with the bit before it, plus a 4-bit Gray code reference table.
Gray code to binary converterConvert Gray code back to plain binary and decimal with a running XOR from the left, plus a 4-bit Gray code reference table.
Decimal to two's complement converterConvert a positive or negative decimal to two's complement at 4 to 128 bits, with hex output, the invert-and-add-1 steps and the allowed range.
Two's complement to decimal converterRead two's complement bits or hex as a signed decimal. The bit width comes from the input length, and the unsigned value is shown for comparison.
One's complement calculatorFind the one's complement of any binary number by flipping every bit, plus the matching two's complement and both values in decimal at the same width.
Signed binary to decimal converterRead one bit pattern four ways: sign-magnitude, one's complement, two's complement and unsigned, and compare the decimal results side by side.
Decimal to ternary (base 3) converterConvert whole decimal numbers to ternary (base 3) with exact math for very large values, plus a step table of repeated division by 3.
Ternary (base 3) to decimal converterConvert any whole number written in ternary (base 3) to its exact decimal value, with a table of each digit, its place value and its share of the total.
Decimal to quaternary (base 4) converterConvert whole decimal numbers to quaternary (base 4) with exact math for very large values, plus a step table of repeated division by 4.
Quaternary (base 4) to decimal converterConvert any whole number written in quaternary (base 4) to its exact decimal value, with a table of each digit, its place value and its share of the total.
Decimal to quinary (base 5) converterConvert whole decimal numbers to quinary (base 5) with exact math for very large values, plus a step table of repeated division by 5.
Quinary (base 5) to decimal converterConvert any whole number written in quinary (base 5) to its exact decimal value, with a table of each digit, its place value and its share of the total.
Decimal to senary (base 6) converterConvert whole decimal numbers to senary (base 6) with exact math for very large values, plus a step table of repeated division by 6.
Senary (base 6) to decimal converterConvert any whole number written in senary (base 6) to its exact decimal value, with a table of each digit, its place value and its share of the total.
Decimal to septenary (base 7) converterConvert whole decimal numbers to septenary (base 7) with exact math for very large values, plus a step table of repeated division by 7.
Septenary (base 7) to decimal converterConvert any whole number written in septenary (base 7) to its exact decimal value, with a table of each digit, its place value and its share of the total.
Decimal to duodecimal (base 12) converterConvert whole decimal numbers to duodecimal (base 12) with exact math for very large values, plus a step table of repeated division by 12.
Duodecimal (base 12) to decimal converterConvert any whole number written in duodecimal (base 12) to its exact decimal value, with a table of each digit, its place value and its share of the total.
Decimal to vigesimal (base 20) converterConvert whole decimal numbers to vigesimal (base 20) with exact math for very large values, plus a step table of repeated division by 20.
Vigesimal (base 20) to decimal converterConvert any whole number written in vigesimal (base 20) to its exact decimal value, with a table of each digit, its place value and its share of the total.
Decimal to base 36 converterConvert whole decimal numbers to base 36 with exact math for very large values, plus a step table of repeated division by 36.
Base 36 to decimal converterConvert any whole number written in base 36 to its exact decimal value, with a table of each digit, its place value and its share of the total.
Decimal to sexagesimal (base 60) converterConvert whole decimal numbers to Babylonian base 60, with places separated by colons like 1:01:01, plus the steps of dividing by 60.
Sexagesimal (base 60) to decimal converterConvert a base 60 number written in places like 1:01:01 or 1,1,1 to its exact decimal value, with a table of what each place adds.
Number base converter (any base 2 to 36)Convert a whole number from any base between 2 and 36 to any other with exact math, plus a table showing the same number in every base from 2 to 36.
Fractional number base converterConvert numbers with a radix point, like 0.1 or 10.5, between any two bases from 2 to 36, detecting the exact repeating block and showing it in brackets.
Number to Roman numerals converterType any number from 1 to 3999 and get its Roman numeral, so 2026 becomes MMXXVI, with each place explained and a lowercase version.
Roman numerals to number converterType a Roman numeral like MCMXCIV and see the number at once (1994), with what each letter is worth. Invalid forms such as IIII are flagged.
Large numbers to Roman numerals (vinculum)Write any number up to 3,999,999 in Roman numerals using the vinculum overline that multiplies a symbol by 1000, such as V̅ for 5000.
Roman numeral calculatorAdd, subtract, multiply or divide two Roman numerals and get the answer in Roman and ordinary digits, with the remainder for division.
Date to Roman numerals converterTurn any date, such as a wedding or birth date, into Roman numerals in day-month-year or US order, with the separator of your choice.
Roman numeral date to normal dateDecode a Roman numeral date such as XXX.IX.MMXXVI into a normal date with the month name and weekday, and check that the date exists.
Number to Egyptian hieroglyph numeralsWrite any number up to 9,999,999 in ancient Egyptian hieroglyph numerals: stroke, hobble, rope coil, lotus, finger, tadpole and the god Heh.
Egyptian hieroglyph numerals to numberPaste Egyptian hieroglyph numerals and get their value in ordinary digits, with a count of every sign from the single stroke to the million.
Number to Babylonian cuneiform numeralsConvert any number up to 12,959,999 into Babylonian cuneiform numerals in base 60, with the sexagesimal places and the signs for each.
Number to Mayan numerals converterWrite any number from 0 to 63,999,999 in Mayan base-20 numerals made of dots, bars and a shell, with the levels stacked top to bottom.
Number to Greek numerals converterWrite any number from 1 to 9999 in Greek alphabetic (Ionic) numerals, such as χξϛʹ for 666, in lowercase or capitals with the keraia mark.
Greek numerals to number converterConvert Greek alphabetic numerals such as ͵βκϛʹ or ΧΞϚ into ordinary numbers, accepting capitals, lowercase and στ for 6.
Number to Hebrew numerals converterWrite any number from 1 to 9999 in Hebrew alphabetic numerals with geresh and gershayim marks, such as ה׳תשפ״ו for 5786.
Hebrew numerals to number converterConvert Hebrew alphabetic numerals such as תשפ״ו or ה׳תשפ״ו into ordinary numbers, handling the thousands mark, final letters and vowel points.
Number to Chinese numerals converterWrite any number up to 999,999,999,999 in Chinese numerals: simplified, traditional and the financial (大写) form used on cheques and invoices.
Chinese numerals to number converterConvert simplified, traditional or financial Chinese numerals such as 二千零二十六 or 壹仟贰佰 into ordinary numbers, including 两 and short forms like 一万五.
Number to Japanese kanji numeralsWrite any number up to 999 trillion in Japanese kanji numerals with 万, 億 and 兆, or in formal daiji (壱弐参拾) for legal documents.
Japanese kanji numerals to numberConvert Japanese kanji numerals such as 二千二十六, 一億二千万 or mixed forms like 3万 into ordinary numbers, with support for daiji 壱弐参.
Number to Attic Greek numerals converterWrite any number up to 99,999 in ancient Greek Attic (acrophonic) numerals: Ι, Δ, Η, Χ, Μ and the combined five signs.
Number to Aegean numerals (Linear B)Write any number up to 99,999 in Aegean numerals used with Linear A and Linear B in Crete and Mycenaean Greece, one sign for each place.
Number to words converterSpell any number in English words, US or UK style, including negative numbers and decimals, up to 21 digits.
Number to ordinal words converterTurn any whole number into English ordinal words, such as 21 to twenty-first and 100 to one hundredth, with the 21st form.
Ordinal suffix generator (st, nd, rd, th)Enter a number to get its correct English ordinal suffix, st, nd, rd or th, with the 11, 12 and 13 exceptions handled.
Check amount in words (dollars and cents)Type a dollar amount and get the written line for a check, with cents as a fraction over 100, plus the full dollars and cents wording.
Words to number converterType a number in English words, such as twelve hundred and five, and get the digits. Handles minus, "and", "a hundred" and point decimals.
Amount in words in English (SAR, AED, KWD)Write an amount in English words in riyals, dirhams, dinars, pounds, dollars or euros, with invoice style and fraction style lines.
Year in words converterWrite a year the way it is spoken in English, such as 1999 as nineteen ninety-nine and 2026 as twenty twenty-six, plus the full cardinal.
Number to words in lakh and croreSpell a number in Indian English with lakh and crore, plus the rupees and paise wording and Indian digit grouping such as 12,34,567.
Number to Arabic words (tafqeet)Convert any whole number into grammatically correct Arabic words, masculine or feminine, from zero to trillions, with Arabic-Indic digits accepted.
Arabic ordinal numbers (1 to 100)Get the correct Arabic ordinal from 1 to 100 in masculine and feminine, such as الحادي والعشرون and الثانية عشرة.
Saudi riyal amount in Arabic wordsWrite a Saudi riyal amount in correct Arabic words with riyals and halalas, the فقط لا غير cheque form and the English wording.
UAE dirham amount in Arabic wordsWrite a UAE dirham amount in Arabic words with dirhams and fils, the فقط لا غير cheque form and the English wording.
Egyptian pound amount in Arabic wordsWrite an Egyptian pound amount in Arabic words with pounds and piastres, correct noun agreement, the cheque form and the English wording.
Kuwaiti dinar amount in Arabic wordsWrite a Kuwaiti dinar amount in Arabic words with dinars and fils to three decimals, plus the cheque form and the English wording.
US dollar amount in Arabic wordsWrite a US dollar amount in Arabic words with dollars and cents, the فقط لا غير form and the English wording for contracts.
Qatari riyal amount in Arabic wordsWrite a Qatari riyal amount in Arabic words with riyals and dirhams, the فقط لا غير cheque form and the English wording.
Omani rial amount in Arabic wordsWrite an Omani rial amount in Arabic words with rials and baisa to three decimals, with feminine agreement for baisa and the cheque form.
Bahraini dinar amount in Arabic wordsWrite a Bahraini dinar amount in Arabic words with dinars and fils to three decimals, plus the cheque form and the English wording.
Number to French wordsSpell any whole number in French words with the rules for quatre-vingts, cents and vingt et un, in France or Belgium and Swiss style.
Number to Spanish wordsSpell any whole number in Spanish words with the rules for cien and ciento, veintiún mil and mil millones, up to below one billón.
Decimal to fraction converterTurn a decimal like 0.375 into a fraction in simplest form (3/8) and a mixed number, or find the closest fraction under a denominator limit.
Fraction to decimal converterConvert any fraction such as 1/6 or 22/7 to a decimal, with the repeating block shown in brackets and its period length.
Fraction to percent converterConvert a fraction such as 3/8 or 1/3 to a percentage, with the exact repeating form and the decimal value.
Percent to fraction converterConvert a percentage such as 12.5% or 150% into a simplified fraction, a mixed number and a decimal, calculated exactly.
Decimal to percent converterConvert a decimal to a percentage by multiplying by 100, such as 0.375 to 37.5%, and see the equivalent fraction.
Percent to decimal converterConvert a percentage to a decimal by dividing by 100, such as 12.5% to 0.125, ready for formulas and spreadsheets.
Equivalent fractions calculatorEnter a fraction such as 6/8 to get its simplest form and a list of equivalent fractions, and check whether two fractions are equivalent.
PPB to PPM converterConvert a concentration from parts per billion (ppb) to parts per million (ppm), a percentage and a decimal: 50 ppb equals 0.05 ppm.
Repeating decimal to fraction converterConvert a repeating decimal such as 0.1666 recurring or 2.4545 recurring into an exact simplified fraction by entering the repeating digits.
Ratio to percent converterConvert a ratio such as 3:5 or 1:1:2 into the percentage each part makes of the total, plus the first part as a percent of the second.
Per mille (‰) to percent converterConvert a per mille (‰) value to a percentage, a decimal and parts per million: 25‰ equals 2.5% and 25,000 ppm.
PPM to percent converterConvert a concentration in parts per million (ppm) to a percentage, a decimal, per mille and parts per billion (ppb).
Percent to PPM converterConvert a percentage to parts per million (ppm), parts per billion (ppb) and per mille: 0.5% equals 5,000 ppm.
Basis points to percent converterConvert basis points (bp) to a percentage and a decimal: a 25 basis point rate rise means exactly 0.25%.
Percent to basis points converterConvert a percentage to basis points (bp), and optionally the change between two rates in basis points, such as 4.5% to 4.75%.
Fractional odds to decimal oddsConvert fractional odds such as 5/2 into decimal and American odds, with the implied probability as a percentage.
Decimal odds to fractional oddsConvert decimal odds such as 1.33 into the exact fractional odds and the simplest matching fraction such as 1/3, plus American odds.
American odds to decimal oddsConvert American (moneyline) odds such as +250 or −110 into decimal and fractional odds, with the implied probability.
Decimal odds to American oddsConvert decimal odds such as 1.91 or 3.50 into positive or negative American odds, with the fraction and implied probability.
Odds to implied probability converterConvert odds in any format, decimal, fractional or American, into the implied probability as a percentage and its complement.
Decimal to scientific notation converterConvert any decimal number to scientific notation a × 10ⁿ and E notation, with optional rounding to a set number of significant figures.
Scientific notation to decimal converterEnter the coefficient and the power of ten to get the full decimal number with every zero, a comma-grouped copy and the normalized form.
E notation to decimal converterTurn E notation such as 1.6E-19 or 6.02e+23 from a calculator, Excel or code into the full, exact decimal number.
Engineering notation converterConvert a number to engineering notation with a power of ten that is a multiple of 3, like 470 × 10⁻⁶, plus the matching SI prefix.
Round to significant figuresRound any number to the number of significant figures you choose and get the result in standard, scientific and E notation.
Significant figures counterCount the significant figures in any number, see which digits count, and get a warning when trailing zeros make the count ambiguous.
Round to decimal placesRound any number to the decimal places you choose, see the rounding difference and a table of the same number at 0 to 6 places.
Round to nearest 5, 10 or 100Round a number to the nearest 5, 10, 100 or any multiple such as 0.05 or 0.25, up, down or nearest, with a table of common multiples.
Truncate number calculatorCut a number at the decimal places you want without rounding, compare it with normal rounding and see the part that was removed.
Banker's rounding calculator (round half to even)Round with banker's rounding: exact ties go to the even digit, so 2.5 becomes 2 and 3.5 becomes 4, compared side by side with normal rounding.
Decimal to IEEE 754 single precision (float32)Convert a decimal number to its 32-bit float (IEEE 754 single) hex and bit pattern, with the value actually stored and the exact error.
IEEE 754 float32 hex to decimalDecode an 8-digit float32 hex value into its exact decimal value and the shortest decimal that maps to it, with bits and value class.
Decimal to IEEE 754 double precision (float64)Convert a decimal number to its 64-bit double (IEEE 754) hex and bit pattern, with the value actually stored and the conversion error.
IEEE 754 float64 hex to decimalDecode a 16-digit double (float64) hex value into its exact decimal value and shortest round-trip decimal, with all 64 bits and the value class.
Lakh and crore to million and billionConvert South Asian amounts in lakh, crore and lakh crore to million and billion, with the full number in international and Indian commas.
Million and billion to lakh and croreConvert thousand, million, billion and trillion to lakh and crore, with the number in Indian commas and split into crore, lakh and thousand.
Indian number format (lakh and crore commas)Write any number with Indian comma grouping like 12,34,56,789 and international grouping, and read it in crore, lakh and thousand.
Short scale vs long scale number namesSee what billion, trillion and larger names mean in the short and long scales, and the matching name in the other scale, to avoid a thousandfold error.
Metric prefix converter (kilo, mega, milli)Convert values between SI prefixes from quecto to quetta, like mega to kilo or micro to milli, with exact results and no decimal errors.
Scientific notation calculatorAdd, subtract, multiply and divide numbers in scientific notation such as (3 × 10⁴) × (2 × 10⁵), with a normalized result and E notation.
Western to Eastern Arabic numeralsTurn every Western digit in your text into the matching Eastern Arabic digit used in the Gulf, Egypt and the Levant, with an option for decimal separators.
Eastern Arabic to Western numeralsChange Eastern Arabic digits in any text to Western 0 to 9, converting the Arabic decimal and thousands separators to a point and a comma.
Western to Persian and Urdu numeralsConvert Western digits in your text to the extended Arabic-Indic digits used for Persian, Dari, Pashto and Urdu, with an optional Arabic decimal separator.
Persian and Urdu to Western numeralsChange Persian and Urdu digits in any text to Western 0 to 9, handy for phone numbers and amounts copied from Iranian or Pakistani sites.
Western to Devanagari (Hindi) numeralsConvert Western digits in your text to Devanagari digits used for Hindi, Marathi and Nepali, keeping letters and symbols as they are.
Devanagari (Hindi) to Western numeralsChange Devanagari digits in Hindi, Marathi or Nepali text to Western 0 to 9 so you can use them in spreadsheets and forms.
Western to Bengali numeralsConvert Western digits in your text to Bengali digits used in Bangladesh, West Bengal and Assam, leaving letters and symbols as they are.
Bengali to Western numeralsChange Bengali digits in any text to Western 0 to 9, useful for mobile numbers and amounts copied from Bangladeshi websites.
Western to Gurmukhi (Punjabi) numeralsConvert Western digits in your text to Gurmukhi digits used to write Punjabi in India, leaving letters and symbols unchanged.
Western to Tamil numeralsConvert Western digits in your text to Tamil decimal digits used in Tamil Nadu, Sri Lanka and Singapore, one digit for one digit.
Western to Thai numeralsConvert Western digits in your text to the Thai digits seen on official papers and calendars in Thailand, leaving letters as they are.
Thai to Western numeralsChange Thai digits in any text to Western 0 to 9 so you can read prices and dates on Thai documents and signs.
Western to Khmer numeralsConvert Western digits in your text to Khmer digits used in Cambodia on riel prices and official documents.
Western to Burmese (Myanmar) numeralsConvert Western digits in your text to Burmese digits used in Myanmar on prices, buses and documents, keeping letters as they are.
Western to traditional Mongolian numeralsConvert Western digits in your text to the digits of the traditional Mongolian script used in Inner Mongolia and formal or artistic writing.
Western to fullwidth digitsConvert ordinary digits in your text to fullwidth digits used in Japanese, Chinese and Korean typesetting so they match the width of CJK characters.
Any script digits to Western digitsChange Arabic, Persian, Indian, Thai, fullwidth and other digits in one text to 0 to 9, with a table of which scripts were found.
Number to Chinese financial numerals (大写)Type an amount to get it in Chinese financial (uppercase) numerals as written on Chinese cheques and invoices, in yuan format or as a plain integer.
Chinese financial numerals (大写) to numberPaste an amount written in Chinese financial numerals such as 壹仟肆佰零玖元伍角 to get its value in ordinary digits, simplified or traditional.
Numbers to circled numbersTurn numbers in your text into circled number symbols from 0 to 50, or filled circles, parentheses or full-stop forms, for neat numbered lists.