About the Forecast Growth Calculator
Simple linear-trend forecast from past values: slope, next values and projected growth.
Also known as: linear forecast, trend forecast, projection calculator.
How to use this calculator
- Enter past values (in order), periods to forecast.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
Least-squares line y = a + b·t
Worked example
Using the values pre-filled in the calculator above:
- Past values (in order): 210, 225, 238, 250, 266, 279
- Periods to forecast = 3
the calculator returns:
- Next period forecast: 292.67
- Trend per period: 13.714