# BASDAI Calculator (Ankylosing Spondylitis Activity)

URL: https://speedycalculator.com/calculators/health/basdai/
Last updated: 2026-10-30

> The BASDAI calculator scores the Bath Ankylosing Spondylitis Disease Activity Index from six questions about fatigue, spinal pain, joint pain and swelling, tenderness and morning stiffness over the past week. A score of 4 or more indicates active disease.

## Inputs

- 1. Fatigue or tiredness
- 2. Neck, back or hip pain
- 3. Pain or swelling in other joints
- 4. Discomfort from areas tender to touch or pressure
- 5. Severity of morning stiffness
- 6. Duration of morning stiffness (hours)

## Results

- BASDAI

## Formula

```
BASDAI = (Q1 + Q2 + Q3 + Q4 + (Q5 + Q6) ÷ 2) ÷ 5
Each question 0–10; morning stiffness duration: 0 h = 0, 2 h or more = 10
```

## Explanation

The BASDAI is the standard patient-reported measure in axial spondyloarthritis. A score of 4 or more, together with specialist opinion, is used to consider biologic treatment.

### How to use the BASDAI Calculator

- **1. Fatigue or tiredness**
- **2. Neck, back or hip pain**
- **3. Pain or swelling in other joints**
- **4. Discomfort from areas tender to touch or pressure**
- **5. Severity of morning stiffness**
- **6. Duration of morning stiffness**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Rate each question on a scale of 0 (none) to 10 (very severe) for the past week.

### Inputs explained

FieldWhat to enter1. Fatigue or tirednessA number2. Neck, back or hip painA number3. Pain or swelling in other jointsA number4. Discomfort from areas tender to touch or pressureA number5. Severity of morning stiffnessA number6. Duration of morning stiffnessIn hours

### Example values

How the main result changes when **1. Fatigue or tiredness** changes and everything else stays at the example values above:

1. Fatigue or tirednessBASDAI2.54.13.754.454.66.254.97.55.1105.6
*Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.*

## Worked example

Inputs — 1. Fatigue or tiredness: 5; 2. Neck, back or hip pain: 6; 3. Pain or swelling in other joints: 3; 4. Discomfort from areas tender to touch or pressure: 4; 5. Severity of morning stiffness: 5; 6. Duration of morning stiffness: 1 hours.

Results — **BASDAI = 4.6**.

## Key terms

- **Axial spondyloarthritis**: Inflammatory arthritis mainly affecting the spine.

## FAQ

**What BASDAI score is active disease?**
4 or more.

**How often should BASDAI be done?**
At each review, typically every 3–6 months.

**What is ASDAS?**
An alternative activity score that also uses CRP or ESR.


## Sources

- [Garrett S et al. A new approach to defining disease status in ankylosing spondylitis: BASDAI. J Rheumatol, 1994](https://pubmed.ncbi.nlm.nih.gov/7699630/)