Septenary to Decimal Converter

Convert Septenary (Base 7) to Decimal (Base 10) with step-by-step solution.

Valid digits: 0123456
255 (Base 7) = 138 (Base 10)
Step-by-Step Solution
1Convert Septenary to Decimal:

Each digit × 7^position:

DigitValuePositionCalculationResult
2222 × 7^298
5515 × 7^135
5505 × 7^05
Sum: 98 + 35 + 5 = 138
2Result:
255 (Base 7) = 138 (Base 10)

Conversion Table

DecimalSeptenaryDecimal
000
111
222
333
444
555
666
7107
8118
9129
101310
152115
162216
202620
324432

255 (Base 7) in All Bases

Number SystemBaseValue
Binary210001010
Octal8212
Decimal10138
Hexadecimal168A
Ternary312010
Quaternary42022
Quinary51023
Senary6350
Duodecimal12B6
Vigesimal206I
Duotrigesimal324A
Hexatrigesimal363U

Popular Conversions

How to Convert Septenary to Decimal

To convert from Septenary (base 7) to Decimal (base 10), multiply each digit by 7 raised to its position and sum.

About Septenary

Days of the week. Uses digits: 0123456

About Decimal

Standard number system. Uses digits: 0123456789