About FROGS
FROGS is a free fetal growth calculator for clinicians and researchers. It turns a birthweight and gestational age into growth centiles, z-scores and charts – using growth standards calibrated to the local population rather than a one-size-fits-all global reference.
How it works
Three steps from measurement to chart – click through to see each one.
What makes FROGS different?
Fetal growth is not one-size-fits-all. FROGS brings together several features that support more accurate and consistent assessment of fetal size and growth.
Growth patterns differ between populations. FROGS is calibrated to your regional population, providing a fairer assessment of whether a baby is growing as expected.
FROGS is designed to show where a baby sits compared with other babies still growing in utero, rather than relying on birthweight-based references.
Babies grow every day. FROGS accounts for this by calculating centiles for each exact day of gestation.
Boys are, on average, larger than girls even before birth. FROGS can account for fetal sex, allowing a more tailored assessment.
FROGS assesses not only fetal size, but also how centile position changes between scans.
A decision-support tool
FROGS supports clinical assessment – it does not replace it. Results should always be interpreted alongside the full clinical picture by a qualified health professional.
Growth centiles and charts – in seconds.
Get in touch
Questions about FROGS, interested in getting involved, or thinking about using it at your service? We'd like to hear from you.
Contact the FROGS team