Hi there, What does the Altimeter 29.92 mean? Any help is greatly appreciated. Thanks in advance.
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Inches of Mercury, Hg or inHg
Old world way of measuring pressure 
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Sorry I’m confused. What kind of pressure? I am new at this.
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Atmospheric pressure in this context - you change the setting so that your altimeter reads the desired value (either feet above ground or feet above sea level).
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Thanks guys for the clarification and replies.
Your altimeter determines your altitude by measuring ambient air pressure relative to air pressure at sea level (standard is 29.92 inches of mercury). However, atmospheric conditions cause ambient pressure to rise or fall, which will cause your altimeter to give incorrect readings.
That’s why ATC will always tell you the new altimeter value. You then set your altimeter’s barometer to said pressure to calibrate it to current position to give you a correct altitude reading.
In North America, above altitudes of 18000 feet, all altimeters are set to 29.92 vs actual pressure. That transition altitude differs in different parts of the world.
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For more information, here is a great video on how the pitot-static system works in your airplane:
I like that video because it’s a tangible representation of what air pressure does to these three gauges.
The pitot-static system drives three of the six instruments in the so-called basic instrument six pack. The static port on the outside* of the aircraft (* usually on the outside, but not always…and then sometimes there’s an Alt Static Air switch that causes the air to come from somewhere else) channels air into these instruments and they adjust based on the air pressure they read from the static port.
Your altimeter is one of these three instruments, and it has a sealed wafer inside it filled with a certain pre-determined pressure. That wafer is surrounded by air from the static port, which causes the wafer to expand and contract based on the difference in pressure. That expansion and contraction drives a gear mechanism (like a watch) that causes the dial on your altimeter to go round in circles.
As Crunchmeister71 said, atmospheric pressure changes, so you need to account for that. That’s what the altimeter reading is about. When you get your METAR or ATIS or talk to ATC, they’ll give you an altimeter reading and you’ll be constantly adjusting it throughout your flight (or at least you should be) to ensure that you’re actually flying at the altitude you think you are.
Next time you’re in a plane, find the BARO knob in the cockpit and give it a twist while looking at your altimeter. Check out what it does to your indicated altitude.
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I agree with you, the video is perfect and your explanation too.
In my opinion, there is no better answer to the question.
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Thank you for the kind words!
That kind of very basic question shows the major lack of tutorial/ documentation in MSFS about the aviation in general.
There is/ will be a lot of new people that knows squat, and it would ve been very convinient to have anything to help them.
** Please, dont tell me that they have to go on YouTube/Google to learn things
I fully agree. Actually, that should be the main purpose of this forum. Rather than constantly criticizing the developers, we should help each other out to make MSFS work. That includes helping new ones to get airborne and get safely back again. So, I applaud the OP for his question and all who shared their experience.
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I just want to thank you all for your support and help. I was very upset with that comment.
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I know it’s hard not to, but don’t take it personally. Never feel shy of asking questions. There are no stupid questions.
When it comes to aviation, there’s a ton to learn. When I got MSFS on launch, I knew very little about it. Reading this forum and asking questions was incredibly helpful. There’s a wealth of knowledge here by both experienced simmer and real pilots will always be willing to help.
I credit both this forum and the wealth of great videos available on YouTube for getting me to the level of understanding I have today. I’m no expert - not by a long shot. But I believe I have a decent foundation and a solid graps of most of the basics. And that’s enough (for now) for me to be able to enjoy the depth of this sim and will carry over whenever I can start taking my actual flying lessons once the pandemic is over and lockdowns are lifted.
@Crunchmeister I noticed multiple times when vary winds that target airports in the mountains are not on the height promised, so now I know why that is. Thanks.
By the way I’ve a key “b” on my keyboard assigned to calibrate the altimeter. Is that the same as ATC action ?
when you press b, it sets automatically your altimeter as how it is, where you are, right when you press it.
and if you are above FL180 it will set it to 29.92
That’s not how it’s supposed to work though. There’s no magic button in your plane to automatically set your instruments to the correct barometric pressure like there is in the sim. That’s why METARs, ATIS and ATC tell you what the current conditions are. It’s up to the pilot to set their flight instruments correctly, and it’s part of the checklist.
When you first start your plane, you should be tuning into ATIS to get the local weather conditions, including pressure, and then settings your instruments (typically more than 1) accordingly. If no ATIS or METAR is available at your airfield and it’s uncontrolled, you should be using a chart to see what your actual altitude is at your location and setting your pressure until your altimeter matches that reading. That’s not 100% accurate, but close enough until you can get on the radio and get an actual reading.
On the planes that do have the “press” on the baro setting, that should reset it to standard 29.92 only, not current atmospheric pressure.
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Gonna try that… I’m thinking for a while to learn that part too. I’m an anarchist flying around atm, radio off 
That’s the beauty of this game. You can fly whatever way you want. You can make it a game and do whatever you want, or you can use it as a simulator and fly by the rules and procedures.