CSV Formula Eval
Add computed columns to a CSV with arithmetic formulas over your existing columns. Runs entirely in your browser, no upload.
CSV formula eval
Add computed columns to a CSV using spreadsheet-style formulas. Reference your
existing columns by their header name — for example total = price * qty or
margin = (price - cost) / price. It runs in your browser; nothing is uploaded.
Formulas
- Write
<column> = <expression>. A new name adds a column; an existing name replaces it. - Separate multiple formulas with
;or newlines. They run left-to-right, so a later formula can use a column an earlier one created. - Expressions support
+ - * / %,^(power), parentheses, and functions likesqrt,abs,min,max,round,floor,ceil,sin,ln, … - Column names used in expressions must be identifier-like (letters/digits/
_, not starting with a digit). Cells that aren't numbers leave a referencing formula blank for that row.
Example
price,qty + total = price * qty → adds a total column = price × qty.
FAQ
Is my data uploaded?
No — it's processed locally with WebAssembly.
Does it work with semicolon- or tab-separated files?
Yes. The delimiter option accepts any single character, or the names
comma, tab, semicolon and pipe. The default is a comma, and the
output is written back with the same delimiter you chose.
What happens when a cell isn't a number?
Any row where a referenced cell fails to parse as a number gets a blank result for that formula — the row itself is kept and all other rows still compute normally. That's also why the first row must be a header: it's how columns get the names your expressions refer to.
Can one formula build on another one's result?
Yes. Formulas run left-to-right, so subtotal = price * qty; total = subtotal * 1.2 works — the second formula sees the subtotal column the
first one just created. Re-using an existing header as the target replaces
that column in place instead of appending a new one.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool csv-formula-eval "price,qty
10,3
5,4" 'formulas=total = price * qty'New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/csv-formula-eval/?data=price%2Cqty%0A10%2C3%0A5%2C4&formulas=total%20%3D%20price%20%2A%20qty&delimiter=%2CMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.