Free · No signup · Runs in your browser
Add acalculated column
Write an arithmetic expression over your numeric columns and append the result as a new column - entirely in your browser.
Write an arithmetic expression over your numeric columns and append the result as a new column - entirely in your browser.
Paste your CSV, write a formula that references columns by name, and download a new file with the computed column appended. Nothing is uploaded - every calculation runs locally in your browser.
Drop in or paste your file. The tool profiles every column and detects which ones are numeric so you can reference them by their exact header name.
Enter an expression like price * qty - discount. Use + - * / and parentheses for grouping. Reference any column by its exact name; wrap names with spaces in backticks. Name the output column whatever you like.
The new column is appended to every row. Rows where an operand is missing, non-numeric, or divided by zero are left blank so bad data never produces garbage. Export clean RFC-4180 CSV.
A spreadsheet formula without the spreadsheet - safe, fast, and private.
The expression is parsed by a small recursive-descent evaluator - never eval or Function. Your formula can only do arithmetic over your columns, nothing else.
Non-numeric cells, missing values, and division by zero yield a blank cell for that row instead of NaN, Infinity, or a thrown error - so the rest of your file stays usable.
Reference columns by their precise header text. Names containing spaces or symbols work too - just wrap them in backticks like `unit price`.
All parsing and computation happen in your browser. No upload, no account, no server ever sees your rows. Close the tab and the data is gone.