Online Tool Store
CSV Computed Column
Add a computed column to a CSV using arithmetic across existing columns, with type handling and blank-value rules made explicit.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Data & CSV
CSV Computed Column
Frontend preview — no upload or external service.
Preview
1,240 rows: total = price × quantity added as a new last column. 18 rows had a blank quantity and are flagged rather than silently totalling zero.
How the CSV Computed Column works
- Paste or load the CSV with its header row.
- Write the expression using the column names exactly as they appear in the header.
- Decide what blanks should do before running it — treating them as zero silently changes your totals.
FAQ
What happens to blank or non-numeric values?
Whatever you choose, and the choice matters. Treating blanks as zero makes a missing quantity look like a genuine zero total, which is why flagging is usually safer for anything financial.
Are numbers stored as text handled?
Values with thousands separators or currency symbols are text, not numbers. Strip them first, or the arithmetic silently produces nothing useful.
Can the expression reference other computed columns?
Add them in sequence — compute the first column, then use its output as input to the next. Chained references in a single pass are where these things get hard to debug.
How we compare
| Feature | Online Tool Store | A spreadsheet | A BI platform |
|---|---|---|---|
| Explicit blank handling | ✓ | Silent default | Varies |
| Flags problem rows | ✓ | ✗ | Sometimes |
| No spreadsheet needed | ✓ | ✗ | ✓ |
| Data stays local | ✓ | ✓ | ✗ |
CSV Computed Column makes blank handling a decision rather than a default, because a blank treated as zero is how a total quietly goes wrong.