Fill Horizontal with Linear Trend Series (Rows)

This tool fills your selected cells with values that follow a linear trend, calculated separately for each row based on the numbers already in that row's selection.

It uses Excel's built-in Fill Series feature with:

• Series in: Rows
• Type: Linear
• Trend: Yes (best-fit line through known values)

How it works:

The tool analyzes the numeric values found within the selected cells in each row, then fills accordingly:

• One value found: Fills left and right with a step of 1.
• Two values, in the first and last cell of the row selection: Fills only the cells between them evenly.
• Two or more values, elsewhere in the selection: Calculates a linear trend and fills all selected cells with the interpolated values. This may overwrite the existing values.

Examples:

• One value:
  • Before: (blank), (blank), 10, (blank), (blank)
  • After: 8, 9, 10, 11, 12
• Two values:
  • Before: 10, (blank), (blank), 40
  • After: 10, 20, 30, 40
• Three or more values:
  • Before: 12, (blank), 50, (blank), 800
  • After: 12, -30.71, 50, 409.66, 800

This is useful for filling missing values, estimating patterns, or applying a numeric trend across columns without writing formulas.

It saves time compared to Excel's manual Home > Fill > Series with Trend option.

For even faster access, assign a custom shortcut via "My Tools & Shortcuts".

Starting this tool

Additional keywords to help you find this tool:
Fill missing values in rows, Autofill linear trend across rows, Fill series horizontally, Fill gaps in row data, Interpolate values in row, Horizontal fill series, Fill blank cells with pattern, Linear trend rows, Autofill missing row values, Apply linear trend left to right, Fill between values in row, Estimate missing values in row, Row trendline fill, Horizontal fill series with trend, Fill missing numeric values, Row interpolation, Auto series left to right

Tip:Alt+P for the previous tool.