How to Auto-Sum Columns in an Online Table

A table that adds itself

Learn how to auto sum columns table with Tablesmit. Learn how to auto-sum columns in an online table with Tablesmit. You are building a budget table. Six rows of expenses. One column for amounts. You reach for a calculator, or you copy the data into a spreadsheet just to get a total.

Tablesmit has a better way: Auto-Sum.

How Auto-Sum works

Any column formatted as Number, Currency, or Percentage can display a running total at the bottom of the table:

1. Click the column header to select the column.
2. Open the Column Type panel in the right sidebar.
3. Set the column type to Number, Currency, or Percentage.
4. Toggle Show sum row on.

A non-editable footer row appears below the table. The footer cell for that column displays the sum of all non-empty cells. The footer is styled in a muted surface colour to distinguish it from data rows.

What gets summed

• Every cell with a valid numeric value in that column
• Positive and negative numbers
• Decimal values

Cells containing text, empty cells, and non-numeric content are ignored. If every cell in the column is empty or non-numeric, the footer shows nothing.

Auto-Sum across multiple columns

Each column is independent. You can enable Auto-Sum on one column or all of them. A table tracking monthly revenue might have Auto-Sum on the Revenue column and the Expenses column, while the Notes column stays text-only.

Auto-Sum in exports

Sum rows are excluded from some exports and included in others:

• PDF — included, styled as the footer
• Excel — included as a formula row (=SUM)
• PNG / JPEG — included, rendered as shown
• CSV — excluded (CSV is raw data only)
• LaTeX — included as a \hline + sum row at the bottom

Auto-Numbering

Related feature: columns with type Number also support Auto-Numbering. Toggle it on and the column fills with sequential integers (1, 2, 3…). Insert a row, and the numbers re-sequence automatically. Cells are read-only while auto-numbering is active — shown with a small lock icon.

When to use Auto-Sum

• Budget tables — total expenses, total revenue, net balance
• Survey results — total responses per category
• Inventory lists — total quantity and total value
• Time tracking — total hours across projects

Any column where the last question is "what is the total?".

Quick start

Select a numeric column. Open Column Type. Choose Currency. Toggle Show sum row. Set up Auto-Sum in Tablesmit — your table gets a running total that updates automatically as you edit.