Starter Forecast

This page reads a sales history CSV and writes a weekly forecast. Each SKU gets one average. Weekly quantities are whole numbers. Slow sellers get 1 unit every few weeks so the total stays within 1 unit of the average times the number of weeks.

The file is processed in this browser and is never sent. The confirmation email does not include your SKUs or sales.

The average uses these rules:

• Each sale moves back to the Monday of its week. Sales from every location are added together, so there is one forecast per SKU.
• The history window is the 12 complete weeks before the plan start week. Sales in the plan start week or later are left out.
• A SKU's first sale week is the first week with net sales above zero. Weeks before that are left out. Zero weeks after that are counted. Weeks used is that count, capped at 12.
• The average is the total of those weeks divided by weeks used. A negative average is set to 0 and flagged. The result is rounded to 2 decimals.
• Weekly quantities are whole numbers. Slow sellers get 1 unit every few weeks so the total stays within 1 unit of the average times the number of weeks. The summary keeps that average, to 2 decimals, next to weeks used, so you can check it with a calculator.

• A rise, a fall, or a seasonal peak stays outside this average. The rate does not climb or fall from week to week.
• A week when you were out of stock still shows only what was sold.
• A new SKU uses the weeks since its first sale, so a short run of sales can move the average a lot.
• One unusual week stays in the average until it falls out of the 12 weeks.

Use a CSV with these columns: order_id, order_datetime, sku, qty, fulfillment_location. Extra columns are ignored. SKUs are kept exactly as written. A quantity such as "1,000" in quotes is read as 1000. A full stop is only for decimals.

Limits: CSV only, 10 MB, 200,000 rows, 5,000 SKUs. Download template_Sales_History.csv. The sample dates are in September 2026. If your plan start week is much later, move the plan start date back or replace the dates.

The preview above is ready. Enter your email to download the forecast and the summary. The email is a confirmation only. It does not include your SKUs or sales.

The articles box starts unticked. The download does not depend on ticking it.