Calculators
Baby Weight Converter
Convert birth weight between grams, kilograms, and pounds and ounces — correctly. Shows whole pounds and whole ounces, never decimal pounds.
Open calculator →Women's Weight Converter
Convert between kilograms, pounds, and stones and pounds. Flags cephazolin dosing consideration at ≥120 kg.
Open calculator →Height & Length Converter
Convert between centimetres and feet and inches. For maternal height at booking and newborn length.
Open calculator →Antenatal BMI Calculator
Calculate BMI from weight and height. Surfaces NZ Referral Guidelines thresholds for obstetric consultation and anaesthetic review.
Open calculator →Age in Hours
Calculate a newborn's age in hours from date and time of birth. Useful for metabolic screening timing, jaundice assessment, and discharge documentation.
Open calculator →Built for clinical practice
These tools exist because the alternatives were frustrating. Baby weight converters that show decimal pounds. Apps that stopped updating. Calculators that don't match how midwives actually communicate results.
Each tool here is built around what matters clinically — correct units, plain language, and results that make sense to families and clinicians alike. The women's weight converter includes a cephazolin dosing flag at ≥120 kg. The BMI calculator surfaces NZ Referral Guidelines thresholds as you type.
All tools are free, require no account, and work on any device.
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