Where do these reference ranges come from?

They reflect commonly taught paediatric reference values used in UK and international resuscitation and early-warning guidance, such as APLS and Paediatric Early Warning systems. Individual local charts may differ slightly, so always defer to your unit's standard.

Why do heart and respiratory rates fall with age?

Younger children have a higher metabolic rate and smaller stroke volume and tidal volume, so they maintain cardiac output and ventilation with faster rates. As the child grows, both rates gradually decline toward adult values.

How is the lower limit of normal systolic blood pressure estimated for children?

Beyond infancy a frequently used rule of thumb for the fifth-centile systolic BP is 70 plus twice the age in years. The bands here use that principle along with conventional reference values for each age group.

Are values outside the range always abnormal?

Not necessarily. Crying, fever, pain, and activity transiently raise heart and respiratory rates. Interpret any out-of-range value in clinical context and recheck when the child is settled before escalating.

Paediatric Normal Vital Signs Reference

Paediatric normal vital signs by age

Children’s normal vital signs change dramatically with age, so a heart rate that is reassuring in a neonate would be alarming in a teenager. This reference shows the conventional normal ranges for heart rate, respiratory rate, systolic blood pressure, and oxygen saturation across paediatric age bands, and flags any value you enter as inside or outside the expected range.

How it works

Each age band carries a stored normal range for each parameter, drawn from widely taught paediatric reference values. When you enter a measured value, the tool compares it against the band’s low and high limits and reports whether it is normal, high, or low.

For each parameter:
  if value < low   -> LOW (below normal)
  if value > high  -> HIGH (above normal)
  else             -> within normal range

A common bedside estimate for the lower limit of systolic blood pressure beyond infancy is 70 + 2 x age(years).

Tips and notes

Always interpret out-of-range values in context: fever, distress, crying, and pain transiently raise heart and respiratory rates. Recheck a settled child before escalating. These ranges support, but do not replace, a structured paediatric early warning score and your local observation charts.