# Measure Yourself!

Today my sister asked me to measure her height so she can calculate her BMI. Being the lazy lout that I am I told her to measure herself. And then I started thinking of ways she could actually measure herself. I am embarassed to admit I could only think of two ways:

1) Let's round out her height to the nearest centimetre (oh yes, metric system! get with it). She should draw a line on the ground and mark of the metres. If she places copies of herself end-to-end -- by marking off her head and then placing her feet there and continuing, etc. -- eventually her head will coincide with an integer metre, allowing her to calculate her height.

2) Run into a pool and record the time her feet enter the water, and when her head passes the surface of the water. Then she measures the height of the ground from the height of the water. Of course she shouldn't jump into the pool, but simply run forward. A simple calculation will give her height.

Of course neither of these ideas is practiceable, but could work in theory. Nevertheless it's quite fun to think of ways she could measure her own height. Can you think of any other ways?

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Gold Member
Today my sister asked me to measure her height so she can calculate her BMI. Being the lazy lout that I am I told her to measure herself. And then I started thinking of ways she could actually measure herself. I am embarassed to admit I could only think of two ways:

1) Let's round out her height to the nearest centimetre (oh yes, metric system! get with it). She should draw a line on the ground and mark of the metres. If she places copies of herself end-to-end -- by marking off her head and then placing her feet there and continuing, etc. -- eventually her head will coincide with an integer metre, allowing her to calculate her height.

2) Run into a pool and record the time her feet enter the water, and when her head passes the surface of the water. Then she measures the height of the ground from the height of the water. Of course she shouldn't jump into the pool, but simply run forward. A simple calculation will give her height.

Of course neither of these ideas are practiceable, but could work in theory. Nevertheless it's quite fun to think of ways she could measure her own height. Can you think of any other ways?

There is an apparatus that is used to measure the vertical leap of an athlete at a sports combine. If she could construct something that would be similar, but taller than herself, she could measure how tall she was.

In the photo, the athlete hits as many horizontal "pegs" as he can in order to measure how far he's traveled off of the ground. If she could do the same, except walk through hers, she'd be able to measure from the ground up to the last vertical "peg" to get an approximate height.

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Well, yes, that would work, but my methods are certainly more fun!

1. Get a pencil and a ruler. Position yourself against the door frame. Use ruler and put it against the door frame and perpendicular against the head. Keep it there. Rotate, mark frame with pencil.

Take a measuring device and measure the height. Delete mark. Repeat 3 times and average.

Simple. Practical. Can be done by anyone. Does not involves NASA devices.

2. Stop being lazy and help her.

Measure the length from fingertip to fingertip (of the middle finger) when she spreads her arms. It's the same as her height.

1. Get a pencil and a ruler. Position yourself against the door frame. Use ruler and put it against the door frame and perpendicular against the head. Keep it there. Rotate, mark frame with pencil.

Take a measuring device and measure the height. Delete mark. Repeat 3 times and average.

Simple. Practical. Can be done by anyone. Does not involves NASA devices.

2. Stop being lazy and help her.

Thank God someone other than me thought of this.

Isn't the point of science to make things easier?

Gold Member
I don't remember qspeechc asking anyone to refrain from offering impractical solutions. Of course there are easier ways to do it, but what would science be without ingenuity, whether practical or not? Have some fun guys, sheesh.

MotoH:

I'd say that we find easier ways to do things by way of using science, but that is not its sole purpose. In science, we endeavor to understand the world around us, whether or not it leads to practical application.

Borek
Mentor
Measure the length from fingertip to fingertip (of the middle finger) when she spreads her arms. It's the same as her height.

It is not. It is close, but different.

tiny-tim
Homework Helper
sisters!

Today my sister asked me to measure her height so she can calculate her BMI. Being the lazy lout that I am I told her to measure herself.

Quite right! What has she ever done for you?

Measure the length from fingertip to fingertip (of the middle finger) when she spreads her arms. It's the same as her height.
That's not accurate. People's arm length and height vary proportionally from person to person. There's a fighter in the UFC who has a measure of 84.5 inches fingertip to fingertip, yet he's only 6'4".

Do what the physicists do, work in units where her height is 1.

-or-

Tell her to lie down on the floor with a book at her feet and a book at her head. Then get up and and measure the distance between the books.

DaveC426913
Gold Member
Do what the physicists do, work in units where her height is 1.

Tell her to lie down on the floor with a book at her feet and a book at her head. Then get up and and measure the distance between the books.

Inaccurate. She will be taller lying down than she is standing up.

DaveC426913
Gold Member
Have her bend over backwards and grab her ankles touching the soles of her feet to the top of her head, forming as circular a shape as possible. Then have her measure the distance from heel to small-of-back. Multiply by pi.

Standing in sun and measuring shadow and then shadow of a known object..

Gokul43201
Staff Emeritus
Gold Member
Inaccurate. She will be taller lying down than she is standing up.
Besides, this is only good for measuring your length, not your height.

Because a ruler can teeter-totter on your head, it's better to just grab a square, like a book, and line the spine against the wall. Stand against the wall and line up the book, then mark in the corner by the spine on the wall and measure the distance up to that.

I also mark where my eyes are and other features, and at a distance I periodically examine the marks to develop a visual height gauge against my own.

Gokul43201
Staff Emeritus
Gold Member
Because a ruler can teeter-totter on your head, it's better to just grab a square, like a book, and line the spine against the wall. Stand against the wall and line up the book, then mark in the corner by the spine on the wall and measure the distance up to that.
Just remember to use a paperback rather than a hard-cover! Unless you have a flat head. Or if you don't care about sixteenths of an inch.

Inaccurate. She will be taller lying down than she is standing up.
Not everyone is as fat as me.

Moonbear
Staff Emeritus
Gold Member
Who cares if her height is accurate if she's only using it to calculate BMI? BMI is only useful on a population basis anyway and would only give a very rough approximation on an individual basis that can generally be determined just by LOOKING at the person.

It's close enough to just stand against the wall, put the pencil on the top of your head and mark the wall to measure it. Sure, you'll be off by the radius of a pencil, less than a 1/4 of an inch, so no big deal.

Who cares if her height is accurate if she's only using it to calculate BMI? BMI is only useful on a population basis anyway and would only give a very rough approximation on an individual basis that can generally be determined just by LOOKING at the person.

This is why Im advocating the mirror.

Mirror mirror on the wall who is fairest of them all ?

Moonbear
Staff Emeritus
Gold Member
This is why Im advocating the mirror.

Mirror mirror on the wall who is fairest of them all ?

Yep. If quspeechc was a good brother, he would just look up and say, "You're fat; there, now you don't need to measure yourself." At least that's what I would have told my sister if she ever asked me something like that (and she's always been skinny as a rail). If I was in a more charitable mood, I might have told her something more like, "You'll never have boobs if you stay so skinny. Go away!"

cronxeh
Gold Member
Yep. If quspeechc was a good brother, he would just look up and say, "You're fat; there, now you don't need to measure yourself." At least that's what I would have told my sister if she ever asked me something like that (and she's always been skinny as a rail). If I was in a more charitable mood, I might have told her something more like, "You'll never have boobs if you stay so skinny. Go away!"

MOONIEEE

*swings off a ceiling fan*

hey hey

If I was in a more charitable mood, I might have told her something more like, "You'll never have boobs if you stay so skinny. Go away!"

Never say never. Cosmetic surgery works wonders.

Have her go to a fair and stand next to one of the if your not this tall signs.

DaveC426913
Gold Member
Who cares if her height is accurate if she's only using it to calculate BMI? BMI is only useful on a population basis anyway and would only give a very rough approximation on an individual basis that can generally be determined just by LOOKING at the person.

It's close enough to just stand against the wall, put the pencil on the top of your head and mark the wall to measure it. Sure, you'll be off by the radius of a pencil, less than a 1/4 of an inch, so no big deal.

We were obliging the OP:
Nevertheless it's quite fun to think of ways she could measure her own height. Can you think of any other ways?

Yep. If quspeechc was a good brother

good sister

However, only a male would exhibit the characteristics described in the OP

Integral
Staff Emeritus
Gold Member
Who cares if her height is accurate if she's only using it to calculate BMI? BMI is only useful on a population basis anyway and would only give a very rough approximation on an individual basis that can generally be determined just by LOOKING at the person.

It's close enough to just stand against the wall, put the pencil on the top of your head and mark the wall to measure it. Sure, you'll be off by the radius of a pencil, less than a 1/4 of an inch, so no big deal.

This only works for normal people. If you are not normal then there will be signifigant error.

Measure the length from fingertip to fingertip (of the middle finger) when she spreads her arms. It's the same as her height.

Strangely, no. With just a very small sampling of people (4) I once discovered that none of their wingspans exactly matched their height. Two of the four, in fact, had a wingspan greater than their height! One by an inch and the other by three inches (a real monkey man)! All done in stocking feet.

Besides, this is only good for measuring your length, not your height.

Okay. Funny! :rofl: