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Guide 12 · Free resources · Marketing and Sales

How to Build a Sales Forecast

A practical approach to forecasting sales, comparing scenarios and tracking results with an editable Excel model.

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English adaptation: This page may provide a shorter overview than the Portuguese original. For the complete text and additional detail, consult the Portuguese version.

Sales forecasts that support better decisions

A sales forecast estimates expected commercial performance over a given period. It should draw on data, documented assumptions and up-to-date information about customers, markets and opportunities. It helps anticipate resource needs and identify deviations; it is not a target that can simply be chosen.

This resource explains the difference between a forecast, a budget and a sales target. It covers historical methods, pipeline forecasting, bottom-up and top-down approaches, seasonality, scenarios and accuracy metrics. It also includes a fictional SME example and instructions for using the Excel model.

What does Guide 12 include?

  • PDF — Complete guide: approximately 1,500 words in 15 sections, including worked examples and sources.
  • Excel — Sales forecasting workbook: seven worksheets covering historical figures, the sales pipeline, forecasts, scenarios, variances and a dashboard.
  • Transparent formulas: historical projections, probability-weighted opportunities, WAPE and forecast bias.
  • Cenários: hipóteses conservadora, base e otimista, sem probabilidades inventadas.

Which forecasting methods are covered?

A historical approach uses previous-period sales and a justified growth rate. Pipeline forecasting weights CRM opportunities by probability. Scenarios examine the effect of different assumptions. Reconcile these methods carefully: adding projected historical sales to the pipeline can double-count revenue.

Example annual forecast

A fictional business with €600,000 in 2025 sales assumes central growth of 6% in 2026, yielding a reference forecast of €636,000. At 1% growth, it would be €606,000; at 12%, €672,000. These are planning scenarios, not performance promises.

How to aceder:How to access the files: both downloads are free. Register for Guide 12 in the guide library; after submitting the request, you can download the PDF and Excel workbook. Consent to receive future communications is optional.

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Related content

The figures in the example and Excel file are fictional. The guide does not replace professional review of company data or accounting procedures.

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