UConn Ankle Brachial Pressure Index Measurement (ABPI) Calculator
Noninvasive physiological test used for the initial diagnosis and monitoring of peripheral arterial disease.
Kelly Rudd, Jennifer Glen, Youssef Bessada
Provided by
OSU Center for Health SciencesMeasuring the ABI
Watch a YouTube video on How to Measure the Ankle Brachial Index
According to Gornik, et al, 2024, the ankle brachial index (ABI) is a simple, noninvasive physiological tests used to establish a diagnosis of peripheral arterial disease (PAD). The ABI is conducted after a history and physical examination identify patients at risk for PAD. Typically, physical examination symptoms or signs of PAD is present. There are limitations of conducting an ABI in the setting of diabetes and chronic kidney disease (CKD), which are associated with noncompressible vessels. Additionally, noncompressible vessels impact the assessment of chronic limb-threatening ischemia.
The ABI may be performed in a vascular laboratory or in an office-based setting using a blood pressure cuff and a Doppler device. Continuous-wave Doppler waveforms or plethysmograph tracings (i.e., PVR) at the ankle are performed. Additional physiological testing is often performed in the evaluation of PAD to supplement the ABI, such as:
- Exercise ABI testing
- Segmental pressures, leg pressures and (PVR and/or Doppler) waveforms
- Toe pressure/TBI
- Perfusion imaging
- Imaging studies (when further definition of anatomy is required, such as to plan revascularization)
The resting ABI is measured in each leg using a blood pressure cuff and a Doppler device to detect blood flow and pressure in the pedal and the brachial arteries. The ABI is the ratio of the higher
systolic pressure in the ipsilateral dorsalis pedis and posterior tibial arteries divided by the higher of the left and right brachial artery systolic pressures. In patients with symptoms of PAD, the resting ABI has a sensitivity of 69% to 79% and a specificity of 83% to 99% compared with imaging studies showing significant arterial stenoses, although the sensitivity is reduced in the presence of diabetes. To learn how to conduct and ABI, watch the video created by Oklahoma State University.
Formula & Interpretation
ABPI = Highest ankle pressure (DP or PT) on the leg/ Highest SBP arm (right or left)
| ABI Value | Interpretation |
| Greater than 1.4 | non-compressible |
| 1.0-1.4 | no PAD |
| 0.91-0.99 | Borderline PAD |
| 0.8-0.9 | Mild PAD |
| 0.5-0.79 | Moderate PAD |
| <0.5 | Severe PAD |
Acronyms
ABPI: Ankle brachial pressure index measurement
DP: dorsalis pedis
PT: posterior tibial
SBP: systolic blood pressure
PAD: peripheral arterial disease
Revision Notes
Revision 5: You do not have the option to enter an already calculated ABPI.
Revision 6: You now have the option to either enter your calculated ABPI or have the app calculate the ABPI for you.
All questions & possible results
Measuring the ABI
Watch a YouTube video on How to Measure the Ankle Brachial Index
Select one
Select one option:
- Enter ABPI
- Calculate the ABPI
- No ABPI is available
Which brachial blood pressures?
Select all that apply:
- RIGHT brachial
- LEFT brachial
RIGHT brachial systolic pressure
A number between 0 and 300 (whole numbers), in mmHg.
LEFT brachial systolic pressure
A number between 0 and 300 (whole numbers), in mmHg.
Which RIGHT ankle blood pressures?
Select all that apply:
- dorsalis pedis (DP)
- posterior tibial (PT)
RIGHT ankle/dorsalis pedis (DP) systolic pressure
A number between 0 and 300 (whole numbers), in mmHg.
RIGHT ankle/posterior tibial (PT) systolic pressure
A number between 0 and 300 (whole numbers), in mmHg.
Which LEFT ankle blood pressures?
Select all that apply:
- dorsalis pedis (DP)
- posterior tibial (PT)
LEFT ankle/dorsalis pedis (DP) systolic pressure
A number between 0 and 300 (whole numbers), in mmHg.
LEFT ankle/posterior tibial (PT) systolic pressure
A number between 0 and 300 (whole numbers), in mmHg.
Which side?
Select all that apply:
- RIGHT
- LEFT
Enter the RIGHT ABPI
A number between 0 and 100.
Enter the LEFT ABPI
A number between 0 and 100.
Possible results
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