If searching the internet about the topic of ideal weight there are many results including various formulas by Robinson, Miller, Devine, Hamwi.

A problem is my measured weight varies by nearly 10 pounds, comparing very first thing in the morning, until after a big lunch, and wearing more clothes.

Which weight corresponds to the formula? Dehydrated, and an empty stomach?

2 Answers 2


The notion of ideal body weight is a ridiculous one not backed up by any kind of science. Robinson, Miller, Devine, and Hamwi are all just made up, based on data from population height and weight tables (so basing it on half-century old average weights, rather than investigating the effect of weight on health), combined with the author's guesswork.

The Devine formula was devised for and used in dosing of Gentamicin, an antibiotic that can become toxic if overdosed, and the dosing for which is dependent on the patient's bodyweight excluding the weight of their fat. But that method has now been replaced with better estimate's of the patient's fat-free mass.

There is no reason to be using an Ideal Body Weight formula, and you certainly shouldn't be using a number predicted by one as a target for weight loss or weight gain.

Other forms of bodyweight measurement, such as tracking trends as part of progress tracking, would never include the weight clothing, and whether measurements were taken before or after eating wouldn't matter, as long as the time of day, fed state, and whether you've urinated of defecated before the measurement were consistent between measurements. In the special case of preparing for a weight class limited sporting event, you'd want to measure yourself in a similar state to how you'd be measured pre-competition.

  • While you are probably right, if a person wants to get some idea about whether they are overweight or underweight it would be helpful if there were a reference to compare with. An ideal weight chart is at least better than nothing. It gives you ballpark estimates. In your answer, are you proposing an alternative to a weight calculator that a non-scientist, non-athlete, has access to that can give them feedback about weight? It sounds like you are saying there is nothing. Except visit a fitness specialist to determine the patient's fat-free mass.
    – Tim Davis
    Aug 8, 2023 at 13:44
  • @TimDavis waist circumference is probably the best tool for assessing whether you're carrying excessive body fat, and BMI for whether you're underweight. But in both cases, the cut-offs are quite arbitrary. Aug 8, 2023 at 13:56

Most likely on an empty stomach.

From experience, for accurate weight checks I try to eat and drink everything I would for the entire day by 7 pm. Unless I consumed a high sodium meal the night before, after sleeping my weight checks are usually spot on.

  • Thank you for the answer. I also think the morning is the best time to check weight.
    – Tim Davis
    Aug 8, 2023 at 13:28

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