Add computed columns to your CSV with math expressions and text operations — derive new fields without Excel formulas.
Free for files up to 5 MB and 10,000 rows. Files are processed in your
browser — nothing is uploaded to a server. No account required.
About Column Calculator
Derive a new column without opening a spreadsheet. Pick two columns and add, subtract, multiply, divide or concatenate them, or pick one column and take its uppercase, lowercase, character length or rounded value. The result lands in a new column whose name you set.
Order exports are the classic gap: unit_price and quantity are both present, line_total is not. Choose the two columns, choose Multiply, name the column line_total. Rows where either value is not a number come out blank rather than as NaN, and division by zero is blank too.
Select Column A, the operation, Column B if the operation needs one, then Calculate and review the preview before downloading.
Related tools
CSV Viewer — Free online CSV viewer to open, search, sort, and paginate large CSV files instantly in your browser — no upload required.
CSV Editor — Free online CSV editor to edit cells, add or delete rows and columns, with undo/redo and instant export back to CSV.
CSV Validator — Validate CSV files online — find missing values, cells that break their column's type, duplicate headers, and mojibake left by a bad export.
CSV Cleaner — Clean messy CSV files online: trim whitespace from every cell, drop rows that are entirely empty, and tidy header names — in one pass, in your browser.
CSV Deduplicator — Find and remove duplicate rows in CSV files online — match across selected columns and export a clean, unique dataset.
CSV Sorter — Sort CSV files online by one or multiple columns, ascending or descending, with stable multi-key ordering and instant export.