/r/estimation

Photograph via snooOG

Ever wondered what the rate of gummi bear combustion needed to power a lawn mower is?

How fast do you need to throw a burrito to make it spontaneously ignite?

A subreddit dedicated to one of the most useful skills in life. Estimation.

This subreddit is dedicated to taking a stab at answering hypothetical, interesting and often untestable questions. In reality, you're never going to get a perfect answer. Some things just can't be tested. That's why estimation is such a valuable skill.


The following types of posts are allowed:

  • Links to reddit posts related to estimation. Please include the actual estimation in the post title. Example

  • Requests for estimations as long as they have the [Request] tag in the title. Self posts are preferred. Example

  • Links to websites related to estimation.


When fulfilling requests

  • List all assumptions made

  • Link to sources wherever possible

  • Use SI units for your final answer

  • Don't downvote because someone's answer is different. As long as they have made appropriate assumptions and done their calculations correctly, their answer is valid.


Reference dimensions

  • Wolfram Alpha (Mobile version doesn't have ads)

  • Length of an everyday car: 4.4 m

  • Weight of an everyday car: 1300 kg

  • Length of a football field: 100 m

  • Volume of an Olympic swimming pool: 2,500 m3

  • Muzzle velocity of a round fired from a 9 mm Glock 17: 375 m/s or 1,350 km/h


Estimation strategies:


Other related subreddits:

/r/estimation

14,892 Subscribers

2

How many hectares of citrus trees to feed a population of 20million?

The population in Syria for example is 20 million, and they have 6 million hectares of arable land, how much of that should be allocated to citrus trees (lemon, oranges, grapefruits)?

0 Comments
2025/01/30
06:17 UTC

0

how much trypsin do i add to a solution with coffee?

i'm trying to create an experiment where i can measure the effect of coffee on hydrolysis of albumin by using the stomach enzyme trypsin and i'm so confused because some people say to use micrograms while other go as far as grams while the volume of the solution remains pretty consistent.. I literally visited tons of articles and i just keep getting more and more confused

0 Comments
2025/01/29
21:13 UTC

2

How dense would this bag in Skyrim actually be? Would it have a substantial gravitational pull?

While playing Skyrim I noticed that the bag that I store my alchemical materials in was a little over 6000 lbs and it got me wondering, if this bag existed in real life with the amount of weight that was in it, would it cause you to be pulled toward it due to having gravity? if so, how much weaker or stronger relative to the Earths gravity would it be?

Because I don't know how to solve this myself but understand you would need the actual specifications for the object, the actual weight is 6052 lbs and the dimensions of the bag are about 5 inches tall and about 2 inches deep (its the bag on top of the alchemy table you get in the Breezehome in Whiterun).

4 Comments
2025/01/17
07:13 UTC

1

how much of us is skeleton?

(I tried to post this in askscience but it was removed for “explicitly asking for a calculation,” so)

I can’t find an answer to this online. Google thinks I want to know how much of our body weight is bones (about 14%, apparently) but I don’t mean in terms of weight, I mean…in terms of space?

If you look at a picture of a skeleton, that’s taking up more than 14% of the average body in terms of real estate. Our whole body is around a skeleton. That’s got to be at least a third of our physical person.

Someone who studied anatomy explain why I’m either right or completely misunderstanding how our bodies are composed.

1 Comment
2025/01/16
13:05 UTC

0

What is the wattage of the LA fires?

Also the total energy released?

In ROT13, my initial guess is [guerr gvzrf gra gb gur fvkgrra wbhyrf. Qvivqrq ol n jrrx, gung'f svsgl tvtnjnggf]. I multiplied fuel/area * average energy density of fuel * total area burned.

I won't put the rest of my analysis into rot13, so spoilers below. Also, maybe errors.

My wattage estimate is about the same as the peak output of the 3 Gorges Dam, and 10x the capacities of the world's other largest power plants. Hurricane wattages are a few orders of magnitude larger. I also estimate that the electrical grid was serving around 10 megawatts to buildings which are now burned, which is 1/5000 my estimate for the fires.

My energy estimate comes out surprisingly close to my estimate of the average solar irradiance over the same time and area. This much energy could boil 0.01 cubic kilometers of water. I think the strategic petroleum reserve has a few hundred times as much energy as my fire estimate. The largest nuclear explosion in history yielded more energy by about an order of magnitude, at 50 megatons of TNT.

Notes:
All my numbers come from the wikipedia, such as https://en.wikipedia.org/wiki/Orders_of_magnitude_(power) and https://en.wikipedia.org/wiki/Energy_density and https://en.wikipedia.org/wiki/January_2025_Southern_California_wildfires

Additional questions:
How do these quantities of energy and power stack up against various earthquakes, tornadoes, etc.?

1 Comment
2025/01/15
11:59 UTC

4

The total area of all the silicon dies ("chips") produced in the world in 2024 would, laid side by side cover an area 3.5x Central Park in New York. About 12 square kilometres/4.5 square miles.

Also; If we assume an average transistor density of 150 million per square millimeter, that adds up to around 1.8*10^21 transistors produced worldwide in 2024. To put that in perspective, that's about 225 billion transistors for every single person on Earth.

In 1947 there were **one** transistor on the entire planet. Today, 78 years later, the total number of transistors in regular use is minimum

50 000 000 000 000 000 000 000

Bonus fun fact:

The most powerful gaming PC in 1995 had around 25 million transistors.

The most powerful gaming PC in 2025 has around 500 billion transistors.

20 000 times more transistors in 30 years.

0 Comments
2025/01/10
16:56 UTC

1

Theoretically how much force is needed for someone to break a volleyball ball by spiking it and how fast does your hand need to travel? I have searched on the internet but the answers are all irrelevant

1 Comment
2025/01/06
19:07 UTC

0

Name objects that are these heights.

Why I need to know? My ocs are 0.5 meters tall and 3.5 meters tall respectively. So I need to know, what kind of object is around 0.5 meters. And what kind of object is also 3.5 meters?

1 Comment
2025/01/03
15:26 UTC

0

How can I sell a reddit account with 5,700 karma ?

21 Comments
2024/12/28
13:27 UTC

2

What would it cost to build a university in 1885?

Hello! I am part of an online political simulation set in 1885 called Thabaat. The economy is recovering from multiple crises, though now it's going well. In Thabaat education is government funded up to the age of 12. Private universities are costly, and parts of the top 5% go there. I would like to know how much it would cost to build and maintain a university in 1885, and how much the founder would have to receive from a government or bank. The country can be compared to the UK and USA economically and socially, though politically it is much more left-wing.

0 Comments
2024/12/25
16:18 UTC

1

What would it cost to build a university in 1885?

Hello! I am part of an online political simulation set in 1885 called Thabaat. The economy is recovering from multiple crises, though now it's going well. In Thabaat education is government funded up to the age of 12. Private universities are costly, and parts of the top 5% go there. I would like to know how much it would cost to build and maintain a university in 1885, and how much the founder would have to receive from a government or bank.

1 Comment
2024/12/25
16:17 UTC

0

What would it cost to build a university in 1885?

Hello! I am part of an online political simulation set in 1885 called Thabaat. The economy is recovering from multiple crises, though now it's going well. In Thabaat education is government funded up to the age of 12. Private universities are costly, and parts of the top 5% go there. I would like to know how much it would cost to build and maintain a university in 1885, and how much the founder would have to receive from a government or bank.

0 Comments
2024/12/25
16:17 UTC

0

Selling reddit accounts !?

So I have seen people selling their reddit account so I was just wondering how much would my account be priced at and how can I sell it ??

3 Comments
2024/12/13
07:25 UTC

0

Karma Account

How much does a 200 karma point account cost? TY.

4 Comments
2024/12/09
13:21 UTC

2

Are there more night lovers then day lovers in the world?

0 Comments
2024/12/08
10:30 UTC

4

How many ancestors does one have going back 10 generations?

So if I consider my parents the first generation and absolutely no one in my family ever married anyone even remotely related to them, I would have 1024 ancestors in the 18th century.
However, for much of the time since then, people lived in much smaller communities with much less (social mobility) and a higher acceptance to marry distant cousins so chances are that there were marriages between people sharing the same ancestors.
In other words in the family tree with 1024 entries, how many of them show up twice because my grandmother and my grandfather had the same great great grandfather for example?

5 Comments
2024/12/03
10:47 UTC

0

The ultimate question

The very existence of this question is an official brain breaker if you aren’t a person with enough time to truly think about it the question is and I quote “ would you rather have unlimited bacon but no games, or games, unlimited games, but no games.” The question itself is well built and though I can only type this message the answer is based on how it’s said the answer to be chosen is number two it’s kinda like combining like terms but with words you have two games and one unlimited games when you combine like terms one cancels out the other leaving unlimited games (better) however bacon but no games being simple but loss of benefit therefore with more possibilities and simply a better option games, unlimited games, but no games wins hope that clears it up

0 Comments
2024/11/28
09:53 UTC

2

[Request] Assume I have a pound of flesh and, through some means, manage to break every single covalent bond in it, leaving me with a pound of assorted mono-atomar carbon, nitrogen, oxygen etc. What kind of ballpark is the ensuing BOOM in when the atoms inevitably recombine?

0 Comments
2024/11/27
16:38 UTC

0

[ Removed by Reddit ]

[ Removed by Reddit on account of violating the content policy. ]

2 Comments
2024/11/11
21:01 UTC

0

How come my gf 5'8 , 85kg is stronger than me 5'4 , 56kg?

Hi I always thought doing running and athletic gains strength. But my gf who is 4 inches taller and 30 kg heavier is stronger than me. She barely worksout .

She has big arms and upper body along with big thighs which are firm .

I tried armwrestling her, she smiled winked and defeated me . I tried lifting her i couldnt but she could with one hand. I was having shock face and she was smirking the whole time.

We tried wrestling and she sat on my chest i tapped out. When i sat on her she casually slammed me on the side. This is leading to a situation where she winks and physically dominates me.

Like when i was studying she came in the room and said hey short handsome and then bear hug me suffocating my face in her belly and laughed while pushing me making me fall to the ground

in general a boy is stronger than girl.

have u faced this or know somethijng like this.

who would win in this scenarior

11 Comments
2024/11/09
03:38 UTC

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