Accuracy Calculator

Calculate accuracy using three different methods for various applications

Use this method when the ratio of patients with and without the disease reflects the prevalence of the illness.

Formula: Accuracy = (TP + TN) / (TP + TN + FP + FN)

Use this method when the ratio of patients with and without the disease does not reflect the actual prevalence of the illness.

Formula: Accuracy = (Sensitivity × Prevalence) + (Specificity × (1 − Prevalence))

Use this method to find accuracy using simple percent error. The greater the error, the lower the accuracy.

Formula: Percent Error = (|Observed Value − Accepted Value| / |Accepted Value|) × 100

ℹ️ About This Calculator ▼

📊

Used for diagnostic tests when the sample reflects the disease prevalence. Calculates accuracy using true/false positives and negatives.

🔬

Used for diagnostic tests when the sample doesn’t reflect the actual disease prevalence. Requires sensitivity, specificity and prevalence.

📏

Used to calculate accuracy in general scientific measurements by comparing observed values to accepted standard values.

Measures how close a given value is to the truth (or the value agreed on and confirmed).

Measures how close the given measurements are to each other – the reproducibility of results.