Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Keebler

macrumors 68030
Original poster
Jun 20, 2005
2,964
249
Canada
Hi,

I'm wondering if anyone has any links to a calculator which helps calc the proper amount of water someone should be drinking based on their height, weight, activity level and age (if age matters or not)?

i googled, but found a bunch of products which you need to buy to calculate water intake. there's gotta be something better out there.

any ideas?

and please don't take this the wrong way, i'm not looking for averages or 'hey, you need to be drinking 2 gallons per day'. i'm looking for something more scientific. i'm only 5'2" so i highly doubt i should be drinking as much as someone taller than little ol' me :)

Cheers,
Keebler
 
Dunno if this is scientific enough, but a quick google around suggests that "new conventional wisdom" is half your body weight (in pounds) in ounces of water. So ... if you weigh 120 lbs, 60 oz. Some sites seem to suggest drinking 75% of your body weight in ounces of water, but that seems to be verging on ridiculousity.

Of course, if true, this would explain my ongoing lack of hydration.
 
There's another thread on this floating about,anyway I'll just repost what I said there,if your pissing 5 or 6 times per day you've got it close enough.There are so many variables that the formula methods aren't accurate in all conditions.
 
There are contrary theories (like mentioned here) that strongly suggest there isn't some easily defined "minimum" amount you need per day.

I subscribe to those theories more than the "x cups per day" ones. I don't think we evolved to need a given amount per day of water. I especially realize that the food you eat, the environment (wind, humidity, temperature), and your activity and metabolism dramatically alter your hydration needs. There is no real "x amount per pound". It all depends.
 
There's another thread on this floating about...
No pun intended.

But I'd agree that standard formulas are difficult to rely upon because there are too many variables such as exercise, temperature, relative humidity that day, etc.

Peterkro's suggestion of relying upon how often you urinate is another reasonable indicator, but you should also take note of the color - lighter is better.

Essentially, everybody is different in terms of how much they should be drinking. Some people will need a lot of water because they eat differently - for example, if your diet contains a high amount of watery foods, such as fruits, your need to drink water would be reduced.

And, of course, if you're thirsty, drink.
 
Peterkro's suggestion of relying upon how often you urinate is another reasonable indicator, but you should also take note of the color - lighter is better.
From the Dartmouth Medical article:
At normal urinary volume and color, the concentration of the blood is within the normal range and nowhere near the values that are seen in meaningful dehydration. Therefore, the warning that dark urine reflects dehydration is alarmist and false in most instances.
Not sure if it's accurate, but the source seems reasonable.
 
From the Dartmouth Medical article:
Not sure if it's accurate, but the source seems reasonable.
But I believe they're discounting its use as an indicator of dehydration, not as an indicator of optimal hydration. But the point is still valid that urine color shouldn't be the sole indication of proper hydration. However, other sources do indicate that lighter urine color is indicative of a more hydrated state.

Of course, I'm not a doctor. I just pee a lot.
 
There has been massive debunking of the concept of 'drink 6 or 7 glasses per day'.

Even the original research that is quoted by everybody never said that. What it looked at was the total amount of water that is taken in, including in all foods. That includes the water content of your beef steak, your cheese and cucumber sandwich etc.

Most foods have a suprisingly high water content - chicken can be something like 40% water, cucumber is 98% water, so this is a substantial amount.

There was then a press release explaining the research, and it tried to provide a visual concept of the total amount of liquid taken in per day, by saying it was the 'equivalent of 6 or 7 glasses per day' (some websites say 2.5 litres per day, others say '13 cups per day'!)

That phrase '6 or 7 glasses per day' is the one that became a viral meme that propagated worldwide. It's rubbish. If you eat a healthy varied diet, plenty of salads and fruits etc, then optimal drinking water may only be a couple of glasses or so per day, which is quite close to what most (not all!) people actually drink. It can vary with how much air conditioning you have around you, local humidity and temperature, how much exercise you take, sweat, how much food you eat etc.

As always, drink what you feel comfortable with, and get to know your own body and its way of communicating with you. Dry lips, dry throat, dark urine are all indicators that may come up well before you actually start feeling thirsty.
 
Per your request for a calculator, the woman (a wannabe scientist) insists I link you to this "Dog Daily Water Requirement" calculator.

She says she knows how to liquefy dogs and cats, but not people. Cheers, anway!
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.