Heart • Stroke • Circulation Awareness
Ankle-Brachial Index Calculator Singapore
The Ankle-Brachial Index, also called ABI or ABPI, is a recognised vascular measurement that compares ankle blood pressure with arm blood pressure.
It is mainly used to screen for possible peripheral artery disease and leg circulation issues. This page is for education and early awareness. It does not diagnose heart attack, stroke, or peripheral artery disease.
Is This a Real Medical Measurement?
Yes. The test is called the Ankle-Brachial Index. It compares the systolic blood pressure at the ankle with the systolic blood pressure at the arm.
A lower ankle pressure compared with the arm may suggest reduced blood flow to the legs. This can happen when arteries are narrowed, a condition known as peripheral artery disease, or PAD.
1. Measure both arms
Rest quietly for 5–10 minutes. Measure the systolic blood pressure, the top number, on the left and right arm.
2. Measure both ankles
Measure the systolic pressure at the left and right ankle. In clinics, this is often performed with Doppler assessment for better accuracy.
3. Compare the ratio
ABI is calculated by dividing ankle systolic pressure by arm systolic pressure. This calculator uses the higher arm reading as the reference.
ABI Calculator
Enter the SYS value only. Do not enter DIA or pulse. Example: if your blood pressure is 128/76, enter 128.
How to Read the Result
ABI should not be read in isolation. Symptoms, diabetes, kidney disease, smoking history, cholesterol, blood pressure, age, family history, and walking tolerance all matter.
| ABI Result | General Meaning | Suggested Next Step |
|---|---|---|
| 1.00 – 1.40 | Usually normal ABI range. | Maintain healthy lifestyle. Seek review if there are symptoms or strong risk factors. |
| 0.91 – 0.99 | Borderline range. | Consider repeat measurement and medical risk review, especially if symptoms are present. |
| 0.41 – 0.90 | Abnormal. May suggest peripheral artery disease. | Arrange review with a GP, polyclinic, cardiologist, or vascular specialist. |
| 0.40 or below | Severe circulation concern. | Seek prompt medical review, especially with pain at rest, cold foot, numbness, ulcers, or non-healing wounds. |
| Above 1.40 | Also abnormal. May suggest stiff or calcified arteries. | Do not treat it as “excellent”. Ask a doctor whether further vascular testing, such as toe-brachial index or ultrasound, is needed. |
The Missing Circulation Check Many People May Not Know About
Most people are familiar with arm blood pressure. Fewer people know that comparing arm pressure with ankle pressure can reveal possible circulation problems in the legs.
This matters because peripheral artery disease is not only a leg issue. It may reflect wider artery disease in the body and should prompt a broader cardiovascular risk review when abnormal.
Why this matters in Singapore
Heart disease and stroke remain major health concerns in Singapore. Ischaemic heart diseases and cerebrovascular diseases, including stroke, are among Singapore’s leading causes of death.
What ABI can and cannot do
ABI can support awareness of possible peripheral artery disease. It does not diagnose heart attack or stroke and should not replace medical screening or professional assessment.
What Should You Do If the Result Is High or Abnormal?
If ABI is low
- Do not panic, but do not ignore it.
- Arrange medical review, especially if there is leg pain when walking.
- Ask about cholesterol, diabetes, blood pressure, smoking history, kidney function, and cardiovascular risk.
- A doctor may consider repeat ABI, Doppler ultrasound, or further vascular assessment.
If ABI is above 1.40
- This is not automatically a good result.
- It may suggest stiff, calcified, or non-compressible arteries.
- This can be more common in older adults, people with diabetes, or people with kidney disease.
- A doctor may consider toe-brachial index or other vascular testing.
Important note about high blood pressure
If your arm systolic reading is repeatedly high, such as 140 mmHg or above, ABI alone is not enough. Record your blood pressure properly and discuss it with a doctor. One reading alone does not diagnose hypertension, but repeated high readings should be reviewed.
When to seek emergency help
If there is sudden chest pain, severe breathlessness, fainting, facial drooping, arm weakness, speech difficulty, sudden confusion, or severe sudden symptoms, call 995 in Singapore immediately.
Medical Disclaimer
This calculator is for general health education only. It does not provide diagnosis, medical advice, treatment, or emergency assessment. ABI results can be affected by measurement technique, cuff placement, artery stiffness, diabetes, kidney disease, and other health conditions.
A proper clinical ABI test may require trained measurement, appropriate cuff size, Doppler ultrasound, and professional interpretation. Always consult a qualified healthcare professional if you have symptoms, abnormal results, or health concerns.
References
-
Ministry of Health Singapore. Principal Causes of Death.
MOH Singapore: Principal Causes of Death -
Singapore Heart Foundation. Heart Disease Statistics.
Singapore Heart Foundation: Heart Disease Statistics -
American Heart Association. How Is PAD Diagnosed?
American Heart Association: Diagnosing PAD -
Mayo Clinic. Ankle-Brachial Index.
Mayo Clinic: Ankle-Brachial Index -
SingHealth. Peripheral Arterial Disease.
SingHealth: Peripheral Arterial Disease -
HealthHub Singapore. Stroke: Controllable Risk Factors.
HealthHub: Stroke Risk Factors