Fractional Shortening Calculator

A fractional shortening calculator helps you find left ventricular fractional shortening, or FS. It uses two heart size values from an echo test. You enter the end-diastolic size and end-systolic size. The tool then gives the FS percent.

What Is Fractional Shortening?

Fractional shortening shows how much the left ventricle gets smaller as it pumps. Think of it like a small balloon. It starts full, then gets smaller as it pushes blood out. FS shows that change as a percent.

This value is often used with echocardiography. It can help describe left ventricular systolic function. It should not be used alone to make a diagnosis.

Fractional Shortening Formula

The core formula is:

Fractional shortening (%) = ((LVIDd − LVIDs) ÷ LVIDd) × 100

Here, LVIDd means left ventricular internal diameter at end-diastole. LVIDs means left ventricular internal diameter at end-systole. Use the same unit for both values, such as mm or cm.

How to Use an Online Fractional Shortening Calculator

1. Enter the LVIDd value. This is the LV size at end-diastole.
2. Enter the LVIDs value. This is the LV size at end-systole.
3. Check the units. Both values must use the same unit.
4. Click the calculate button.
5. Read the FS result. The answer appears as a percent.

The tool does the math for you. So, you don't need to work through the formula by hand.

Example Fractional Shortening Calculation

Suppose the LVIDd is 50 mm. The LVIDs is 35 mm.

First, find the size change:

50 − 35 = 15 mm

Now use the formula:

FS = (15 ÷ 50) × 100

FS = 30%

So, the fractional shortening is 30%.

Final Verdict

A fractional shortening calculator makes this heart size math quick and clear. You only need LVIDd and LVIDs. Enter both values with the same unit. Then the tool gives the FS percent.

FS is one part of an echo report. A doctor should review it with other findings and the full clinical picture.

FAQs

What does a fractional shortening calculator do?

It calculates FS from LVIDd and LVIDs values. It reports the change as a percent.

What is the formula for fractional shortening?

Fractional shortening (%) = ((LVIDd − LVIDs) ÷ LVIDd) × 100.

What do LVIDd and LVIDs mean?

LVIDd is the LV internal diameter at end-diastole. LVIDs is the LV internal diameter at end-systole.

Can I use mm or cm?

Yes. Both values must use the same unit. The unit cancels in the ratio.

Is fractional shortening the same as ejection fraction?

No. They are different measures. FS uses a change in LV diameter. Ejection fraction uses a change in LV volume.

Can this calculator diagnose a heart problem?

No. The result is a calculation, not a diagnosis. A health professional should review the result with other clinical data.