What did the royal baby really weigh?

One of the most infuriating practices of the British media is to translate the proper medical data recorded by the hospital (in  kilograms, naturally) into the obsolete units that were once used by our grandparents or great-grandparents.  Thus, our future head of state is described as weighing in at “8lbs 6oz”.  So how much is that, and is it a lot or a little?

The National Health Service is supposed to work entirely in metric units.  This principle was reinforced in an exchange in the House of Lords some years ago, when Baroness Thornton assured her questioner, Lord Walton of Detchant, that in order to prevent possibly catastrophic accidents over wrong dosage, the rules requiring metric-only scales were to be strengthened. See http://www.publications.parliament.uk/pa/ld200910/ldhansrd/text/100225-0001.htm#10022584000562.  (The point is that drugs are prescribed in milligrams and relate to body mass in kilograms.  Any additional conversions from or to imperial units would introduce a source of error and are therefore strictly forbidden).

My own son was born at the Queen Elizabeth Hospital in Birmingham in 1975, and I still have the ticket that was attached to his cot and cross-referenced to his wrist band (obviously to prevent babies being presented to the wrong parents).  This is illustrated below (I have redacted his mother’s name).

It can be seen that his weight was given as 3.92 kg – no mention of pounds or ounces.  That was nearly 40 years ago.  Yet still the British media* dumb down this information and translate it into units that are not used in other walks of life (give or take the odd street market trader).  It is as if there is an unspoken conspiracy of the media to prevent British people from progressing into the 21st century.

So what is the answer to the headline question?

8lbs 6oz can be converted (somewhat laboriously) to approximately 3.8 kg.  We cannot be more precise (a) because an ounce is about 28 g, so rounding to the nearest ounce gives a range of 3.786 to 3.814 g; and (b) the imperial figure is itself a conversion from the original metric data, and converting backwards and forwards and then rounding to the nearest whole number inevitably results in loss of precision (and accuracy).

An average newborn baby weighs about 3.4 kg (though the “normal” range is from 2.5 to 4.6 kg).  So the royal baby (like my son) was above average weight at birth, but well within the “normal” range.


*To be fair, the media got their information from the public relations department of the hospital, who in turn issue the information in lbs and oz (presumably because they think this is what the media want).  I actually telephoned the St Mary’s Hospital press office to ask for the birth weight in kilograms, but the respondent was clueless, suggesting that I could convert from the imperial amount, adding that they were unable to release medical information on individual patients.

[Actually, if the last statement is true, then the information may have come from the Palace PR department, in which case the same strictures apply to them. – Erithacus]

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52 Responses to What did the royal baby really weigh?

  1. Daniel Jackson says:

    The question to Jake is, why would the metric mass of the baby be a medical secret? If they give out a fake imperial weight, why not a also a fake metric mass? Real or fake, why are they hiding the metric value from the public as if it doesn't exist?

  2. Jake says:

    @Daniel Jackson

    I agree with what you say. I wish I had an answer to your question.


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