Deforestation Rate Calculator
Enter a forest area at two points in time and the number of years between them to calculate the annual rate of deforestation and the total area lost.
What Is the Deforestation Rate?
The deforestation rate measures how quickly forest cover is being lost over a given period, usually expressed as a percentage per year. It’s a key indicator used by organizations like the UN Food and Agriculture Organization (FAO) to track forest loss at national and global scales.
The Formula
This calculator uses the compound rate of change formula commonly used in FAO forest resource assessments: r = [(A2 / A1)^(1/t) − 1] × 100, where A1 is the initial forest area, A2 is the final forest area, and t is the number of years between measurements. A negative result indicates net forest loss; a positive result would indicate net forest gain (reforestation exceeding loss).
How to Use the Result
This rate assumes a roughly constant proportional rate of change between the two measurement points, which may not capture short bursts of clearing or recovery within that window. For rigorous analysis, deforestation rates are best derived from satellite-based forest monitoring data over consistent time intervals.
- For general educational and estimation purposes only.
- Official deforestation statistics rely on standardized remote-sensing methodology, not simple two-point comparisons.