Percent Decimal Converter

About this tool

Percent Decimal Converter rewrites a pasted column or delimited table between percentage-side values and decimal fractions. Use it for spreadsheet columns, analytics exports, finance rates and configuration files where 12.5% needs to become 0.125, or where a decimal fraction like 0.125 needs to become 12.5%.

The conversion is exact for plain decimal input: the tool shifts the decimal point on the digits you typed instead of multiplying a binary floating-point number. That keeps 0.1 as exactly 10%, not 10.000000000000002%, and keeps 12.345% as exactly 0.12345.

Worked example

Input:

rate
12.5%
7%
0.5%

With Direction = Percent side → decimal fraction, the output is:

rate
0.125
0.07
0.005

Going the other way, 0.125 becomes 12.5%. Leave Direction on Auto-detect per cell when a column is mixed: cells ending in %, ‰, bp or bps are converted down to decimal fractions, while bare numbers are converted up to the selected percent-side unit.

Options

• Percent-side unit controls how far the decimal point moves: percent (%) moves two places, per mille (‰) moves three, and basis points (bps) moves four.
• Columns to convert can be blank for every column, a comma-separated list of one-based indices such as 2,4, or header names such as rate,share when the header option is on.
• First row is a header keeps row 1 unchanged and enables header-name column selection. Turn it off for a headerless list.
• Delimiter accepts comma, tab, semicolon, pipe or any single character. The same delimiter is used for output.
• Decimal places from 0 to 12 rounds and pads to a fixed width. -1 is exact mode with no rounding or padding.
• Trim trailing zeros turns a fixed width into an “at most” width after rounding, so 50% with decimals=4 can become 0.5 instead of 0.5000.
• Append suffix adds %, ‰ or bps when converting up to the percent-side unit. Turn it off when the column heading already says percent.

Limits and edge cases

• Input is limited to 5 MB.
• Plain decimal numbers are converted. Text, blank cells, currency values and scientific notation are copied through unchanged rather than guessed.
• Thousands separators in quoted cells are tolerated, for example "1,234.5%".
• The tool preserves row order, selected/unselected columns and the chosen delimiter. CSV quoting may be normalized by the CSV writer when fields need it.
• Comma decimal notation such as 12,5% is not parsed as twelve point five; use a dot decimal (12.5%) and choose a semicolon delimiter for European-style CSV exports.

Everything runs locally in WebAssembly in your browser; your table is not uploaded.

FAQ