Formula Errors

Calculate Average Weekly Equipment Increase Over Four Weeks in Excel

Maira Mehtab Sep 22, 2026 868 views

Question details

The user needs a formula to calculate the average weekly increase in equipment hours over the previous four weeks, specifically for a spreadsheet layout that uses exactly one column per date.

Product: Excel
Device & OS: not provided
Scenario: Tracking weekly equipment hours and calculating the average weekly growth over a four-week period based on a horizontal date layout.
Observed behavior: When adapting previous formulas (which assumed two columns per date) for a single-column layout, the formula returns a #VALUE error unless the offset is correctly adjusted to three columns.

Before you start

Verify that your spreadsheet dates are arranged consecutively in single columns and identify the exact cell ranges containing your date headers and equipment data rows before applying the formula.

Solution 1Recommended

Use LET, XLOOKUP, and OFFSET for Single-Column Date Layouts

This solution uses a combination of lookup and offset functions to find the current hours and compare them against the value from four weeks ago, then calculates the average increase.

By utilizing the LET function, you can store the result of the XLOOKUP as a variable ('hrs'). You then use the OFFSET function to look back at the data from four weeks prior. Since the layout has one column per date (or week), an offset of -3 columns correctly points to the start of the four-week period.

Select the target cell

Click on the cell where you want the average equipment increase to be displayed.

Input the combination formula

Type the formula: =LET(hrs,XLOOKUP($C8,$C$8:$C$100,XLOOKUP($D$4,$F$7:$Q$7,$F$8:$Q$100)),(hrs-OFFSET(hrs,,-3))/4) into the formula bar.

Adjust the ranges to match your workbook

Modify the lookup ranges ($C$8:$C$100, $D$4, $F$7:$Q$7) to correspond with the actual data and date header ranges in your specific spreadsheet.

Apply the formula

Press Enter to calculate the average. Ensure you haven't accidentally deleted columns that the OFFSET function relies on, as this can break the calculation.

Preventing #VALUE Errors: If you receive a #VALUE error, verify that your workbook uses exactly one column per date. If your layout previously used two columns per date, the offset value must be updated to reflect the new structure.

Efficient Spreadsheet Data Analysis

Calculate Weekly Averages Seamlessly in WPS Spreadsheet

WPS Spreadsheet fully supports advanced dynamic array formulas like LET and XLOOKUP, making it easy to perform complex date-based calculations, offsets, and performance tracking.

1. Open your dataset in WPS Spreadsheet: Launch WPS Office and open the workbook containing your weekly equipment hours.
2. Enter the formula: Select the target cell and paste the XLOOKUP and OFFSET combination formula into the formula bar.
3. Calculate and copy: Press Enter to get the average, and then drag the fill handle down to apply the calculation to other equipment rows.

Fully compatible with Microsoft Excel formulas and .xlsx formatsNative support for modern functions including LET, XLOOKUP, and OFFSETFast processing speeds for large datasets and complex tracking sheetsLightweight, user-friendly, and free to use

microsoft office alternative - wps office

Frequently Asked Questions

Why does my equipment average formula return a #VALUE error?

A #VALUE error usually occurs if the OFFSET function references an invalid range or if the column layout has changed. For example, if you originally had two columns per date and switched to one, the column offset number must be adjusted to match the new layout.

What does the -3 mean in the OFFSET function?

In a spreadsheet with one column per week, an offset of -3 moves the reference three columns to the left. Comparing the current week to the value three weeks prior creates a four-week span, allowing you to find the difference over that exact period.

Can I use this formula if my dates are arranged in rows instead of columns?

Yes, but you will need to adjust the OFFSET function to offset rows rather than columns. Instead of OFFSET(hrs, , -3), you would use OFFSET(hrs, -3, 0) to look three rows up.

Are LET and XLOOKUP available in all versions of spreadsheet software?

LET and XLOOKUP are modern functions available in WPS Office, Microsoft 365, and newer versions of Excel (2021 and later). If you are using an older version, you may need to use a combination of INDEX and MATCH instead.

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