Previous Period Comparison

Previous Period Comparison puts your retailers side by side for one stretch of whole weeks, and sets each against a comparison period. Use it to answer “are we up on last year, and where?” in a single chart.

Shown on demo data.

What it shows

• One pair of bars per retailer: Previous Year (or Previous Period) and Current Period.
• The % change above each pair, green for growth and red for a fall.
• Revenue (£) or units, for all your SKUs or one SKU.

How it’s worked out

% change = (current period minus comparison period) ÷ comparison period × 100

• The change is shown to 2 decimal places.
• Every period is made of whole weeks, Monday to Sunday.
• Vs Previous Year compares the same week numbers a year earlier: weeks 10 to 21 this year against weeks 10 to 21 last year.
• Vs Previous Period compares the same number of weeks, ending just before the current period starts.

The time periods are:

• Last Week and Last 4, 12, 26 or 52 Weeks: complete weeks, ending last Sunday.
• Year to Date: from the week containing 1 January to the end of this week, so it includes the current, unfinished week.
• Last Year: from the week containing 1 January last year to the week containing 31 December.
• Custom Time: the weeks you pick.

Which retailers have it

It’s one page under All Retailers, covering these retailers where your brand is supplied:

• Asda
• Morrisons
• Ocado
• Sainsbury’s
• Tesco
• Tesco ROI
• Waitrose

Booths, Holland & Barrett and CLF aren’t on this page yet.

Using the page

1. In the menu, open All Retailers and choose Prev Period Comparison.
2. Retailers: all of yours are ticked. Untick any you want to leave out.
3. Select SKU: pick one SKU, or leave it on All.
4. Metric: Revenue or Units.
5. Time Period: Year to Date is the default. For Custom Time, click the date box, pick a start and an end week, and click Apply.
6. Comparison: Vs Previous Year (the default) or Vs Previous Period.

The page doesn’t save your choices. It opens on the defaults each time.

Full View adds a table with a row for each period and a column per retailer. Download gives you the same figures as a CSV.

Reading the numbers

• Year to Date reads low early in the week. It includes the current week as far as it’s loaded, against the same week last year in full.
• +0.00% can mean there’s nothing to compare with. A retailer with no sales in the comparison period shows +0.00%, not a real change.
• A retailer with no sales in the current period isn’t shown, even if it sold in the comparison period.
• Ocado data starts in the week of 27 October 2025, so any comparison reaching further back reads high. Year to Date against last year compares properly from January 2027.
• Waitrose weeks run Sunday to Saturday, so they’re a day out of line with the other retailers.
• The table’s Total row adds the two periods together. Read the two period rows instead.

Tip

To see which SKUs are behind a retailer’s change, open that retailer’s Sales page and look at Sales by SKU.