Precisão e Recall
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
P=TP/(TP+FP), R=TP/(TP+FN)
About this calculator
The Precision and Recall calculator is a fundamental statistical tool in machine learning and classification model evaluation. It enables the calculation of two crucial metrics: Precision and Recall. Precision is the ratio of true positives (TP) to the sum of true positives and false positives (FP), indicating the model's accuracy. Recall, on the other hand, is the ratio of true positives to the sum of true positives and false negatives (FN), reflecting the model's ability to detect all relevant cases.
These metrics are calculated based on the formulas: Precision (P) = TP / (TP + FP) and Recall (R) = TP / (TP + FN). It's essential to understand that high Precision values do not necessarily imply high Recall values and vice versa. The choice of one over the other as a primary metric depends on the context and objectives of the model. For instance, in medical diagnostics, Recall is often prioritized to ensure no case is erroneously dismissed.
When using this calculator, it's important to consider common concerns related to the interpretation of these metrics. A model may exhibit high Precision, but if false negatives are severe or frequent, a low Recall can be problematic. Similarly, a high Recall can be achieved at the expense of low Precision, resulting in many false positives and wasted resources.
To effectively utilize this calculator, it's crucial to have a clear understanding of true positives, false positives, and false negatives in the context of your specific problem. This ensures that the calculated metrics are correctly interpreted and meaningfully applied to improve model performance.
Frequently asked questions
What is Precision in a classification model?
Precision is the ratio of true positives to the sum of true positives and false positives, indicating the model's accuracy.
Why is Recall important in certain contexts?
Recall is crucial in contexts where it's vital to detect all relevant cases, such as in medical diagnostics, to avoid false negatives.
How to interpret a model with high Precision and low Recall?
A model with high Precision and low Recall is accurate but fails to detect many relevant cases, indicating a tendency towards false negatives.
Can I improve Precision and Recall simultaneously?
Yes, by adjusting the model and its settings, but often improvements in one metric can affect the other.
What are the limitations of Precision and Recall metrics?
Limitations include dependence on class distribution in the dataset and the need to define what constitutes a true positive, false positive, and false negative.