# Shock Index Calculator

URL: https://speedycalculator.com/calculators/health/shock-index/
Last updated: 2026-10-25

> The shock index calculator divides heart rate by systolic blood pressure. A value above about 0.9–1.0 can signal hidden blood loss or shock even when blood pressure still looks acceptable.

## Inputs

- Heart rate (bpm)
- Systolic blood pressure (mmHg)

## Results

- Shock index

## Formula

```
Shock index = heart rate ÷ systolic blood pressure
```

## Explanation

Heart rate often rises before blood pressure falls, so their ratio picks up early warning signs.

### How to use the Shock Index Calculator

- **Heart rate**
- **Systolic blood pressure**

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

### How it works

Divide the pulse in beats per minute by systolic pressure in mmHg.

### Inputs explained

FieldWhat to enterHeart rateIn bpmSystolic blood pressureIn mmHg

### Example values

How the main result changes when **Heart rate** changes and everything else stays at the example values above:

Heart rate (bpm)Shock index47.50.4371.250.65950.86118.751.08142.51.31901.73
*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 — Heart rate: 95 bpm; Systolic blood pressure: 110 mmHg.

Results — **Shock index = 0.86**.

## FAQ

**What is normal?**
About 0.5–0.7 in healthy adults.

**Is it used for children?**
Age-adjusted versions exist because normal heart rates differ in children.

**What formula does the Shock Index Calculator use?**
Shock index = heart rate ÷ systolic blood pressure.