Vigesimal (base 20) to decimal converter
Paste a number in vigesimal (base 20) to get its decimal value, worked out place by place. Handy for exercises and for checking encoded values.
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How to use it
- Enter number in base 20.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Value = sum of (digit × 20^position), with position 0 at the far right. Example: 516 = 5×20^2 + 1×20^1 + 6×20^0 = 2026.
Example
Inputs: Number in base 20 = 516. Result: Decimal value: 2026; With thousands separators: 2,026; Decimal digits: 4.
516
2026
Limits and caveats
- Whole numbers only, up to 1000 digits; a radix point is not accepted here.
- The place value table appears for inputs up to 60 digits.
Questions about this tool
How do I convert vigesimal to decimal by hand?
Multiply each digit by 20 raised to its position, starting at position 0 on the right, then add the results. For example 516 in base 20 equals 2026.
Does this tool read Maya numerals?
No. It writes base 20 digits as 0 to 9 then A to J. Maya numerals use dots and bars, and their Long Count calendar uses 18 instead of 20 in one place.
Which symbols are allowed in base 20?
The digits 0 to 9 and the letters A to J; spaces are ignored. Any other symbol triggers a message that names it.