Sales Forecast Calculator

How it is calculated

The tool compounds your current sales forward at a fixed growth rate per period: forecast = current sales × (1 + growth % ÷ 100)periods. Total growth is (forecast ÷ current sales − 1) × 100. Current sales is the figure for one period, in dollars, and the growth rate is applied to each period in turn. A period can be a month, a quarter or a year, as long as the growth rate uses the same unit. Periods may be a fraction (2.5 periods at 4% takes $50,000 to $55,151.00). Current sales and periods cannot be negative, and a growth rate of −100% or lower gives no result. A negative rate above −100% is allowed and shrinks the forecast. Zero periods returns today's figure. The tool assumes the same rate every period, with no seasonality, so use it as a baseline rather than a prediction.

Common mistakes

• Entering an annual growth rate with a number of months. The rate and the period must use the same time unit, so convert a yearly rate to a monthly one first.
• Adding the rates instead of compounding them. Six periods at 4% is 26.53% in total, not 24%.
• Treating the forecast as a prediction. Seasonality, price changes and market limits are not in the formula.
• Using this period's unusually strong or weak sales as the starting point, which carries that distortion through every later period.
• Entering a decline of 100% or more, such as -100 for sales that fall to zero. A growth rate of -100 or lower gives no result.