How to find the best sensitivity
We get a lot of questions about what sensitivity people should use in order to play at their best, and the answer is usually quite short: it's up to you. Of course that's not a very useful answer if you're completely new to (competitive) gaming so in this article we'll go over some 'best practices' when it comes to sensitivity as well as give you a couple of ways to work your way towards your very own perfect sensitivity.
Before we get started it's important that you know the difference between the sensitivity setting in games and your 'true sensitivity.' Different games use different ways to calculate sensitivity, so a sensitivity level of '2' might be much faster in one game versus another game and on top of that different mice can have different hardware sensitivities (see: 'what is DPI & eDPI') so when people talk about sensitivity in the general sense they're speaking about how far you have to move your mouse (regardless of which game you're playing) in order to make it travel a certain distance in the game.
To compare the true sensitivities of different people playing the same game we can use eDPI, to compare across multiple games cm/360 (how far your mouse has to travel before you've done a 360 ingame) is often used. This is just a bit of background info, since all of this doesn't really have anything to do with finding your own personal overall sensitivity but it is very handy to know when discussing the subject.
On high versus low sensitivies
Games that require more flicking and constant spins tend to have pros favor a higher sensitivity than games where it's more about holding angles and perfect crosshair placement so there is no overall range of perfect sensitivities that works for all games.
Something that we've noticed over the years is that a lot of people who are new to competitive gaming or not as experienced with shooter games use a sensitivity that's way higher than what any pro uses. Of course it's okay to use whatever you want, but there is a reason pads like the G604 (pictured on the right) are the standard size for all games that we analyze. Take a look at tournaments: almost no pro is using one of those envelope-sized mousepads because they're just too small to accommodate the large swipes that are sometimes required, and this is true even for games with higher average sensitivities.
While sensitivity is personal there's definitely an upper limit (and a lower limit, but people who have their sensitivity way too low aren't common) so if you find that you can spin your character around multiple times by moving your mouse just a couple of millimetres you're going to want to think about lowering your sensitivity.
People often fall into the trap of thinking that they need to be able to react quickly and that, as such, a higher sensitivity is plainly better, but precision matters too. With a super high sensitivity you're just not going to be able to make the necessary micro adjustments when you've overaimed at a target or what have you. Once again: there is a reason that practically every pro uses a large mousepad and that's because they need the space. We're not saying you have to blindly copy the pros, but if over 1500 analyzed professional players are doing one thing there's got to be a reason for that.
So, in short: yes, sensitivity is mostly down to personal preference but there are definitely upper limits where you're actively hindering your ability to make small adjustments that are necessary for reliable and precise aiming. There's also a limit on the lower end but our experience learns us that the vast majority of people who 'need' (it's still up you, of course) to make adjustments have to lower their sens.
Finding your perfect sensitivity
It's important that your sensitivity allows you to at least make a 180 flick with relative ease (if you need to lift your mouse to do a 180 you need a higher sens or a bigger pad) while still allowing you to track targets with relative ease. Of course things like crispy flicks and perfect tracking have to do with practice as well so don't expect there to be a magic sensitivity that allows you to land shots like pros who have been playing for thousands of hours right from the get-go. Having a correct sensitivity (for you) is merely a tool in your arsenal on the way to having great aim.
Bear in mind that changing sensitivities super often isn't something we'd recommend. Tiny adjustments (lowering your sens when you've changed to a lighter mouse, for example) are pretty easy to get used to but large changes will mess with your muscle memory. If you're coming from an outrageously high sensitivity and want to get into the 'normal' ranges we recommend going cold turkey, as gradually lowering your overall sens will just lengthen the process of arriving at and getting used to your perfect new sensitivity.
It might seem daunting at first to lower your sensitivity so drastically but almost everyone who tries it will never go back to their previous 'hyper high' sens so it's definitely worth it.
The PSA Method
Something that's often recommended is the so called 'PSA method' whereby you find your Perfect Sensitivity Approximation ('PSA') by first determining the sensitivity that allows you to do exactly one 360 by going from one end of your pad to the other and then doing a bunch of testing with sensitivities on the higher and lower ends of that starting sens in order to eventually come to an average perfect setting.
This is great if you have absolutely no idea on where to start but it does take quite a bit of time to get through the 'calibration' phase and the PSA method pretty much relies on you having a 'standard size' mousepad so it's not faultless. Still: it's something that we can recommend to get a starting point, so you can absolutely try it out.
Using (average) pro sensitivities
Pro players have had thousands of hours of practice, so it's not unreasonable to think that they know what a good sensitivity is, right? Of course that's true, but we never recommend to just outright copy whatever your favorite pro is using. What works for them might not work for you. Something you can do is take a look at the average (or median) sensitivity (make sure you're looking at eDPI though, and not just ingame sensitivity) of the pros in your game of choice and use that as a starting point for your sensitivity.
Hop into an empty server or practice range/map, set the sensitivity, start moving around, and try to see if the sensitivity allows you to track a non-moving bot (or object, or bullet hole, or anything static in the gameworld) while still allowing for comfortable flicks and turns. If you find tracking really easy but have issues making quick turns or flicks then you can raise your sens a bit, if it's the opposite you can lower it. Experimenting a bit this way can get you to a nice and comfortable sensitivity setting.
Some people just like to set a sensitivity and leave it at that. For CS:GO, for example, you could pick the median sensitivity/eDPI and get to it. Others just go in the game and tweak the sensitivity a bit until they've arrived at something they find moderately comfortable.
This isn't something that we'd recommend if you're going to be serious about shooters but the 'don't overthink it' school of thought certainly has merits. In the end, getting your perfect sensitivity also comes down to getting used to that sensitivity, and as long as you're not at an extreme end of the spectrum it's possible to get used to pretty much anything.
As you've been able to gather: most of this stuff comes down to personal preference. That being said there is definitely a point where your overall sensitivity is objectively too high for shooters. Even pros who are known in their scene for having 'an outrageously high overall sensitivity' (like woxic in CS:GO) have a way lower overall sens than most of the casual gamers (we don't mean this as an insult at all) who come to us for advice on aiming/sensitivity. If you feel spoken to and you want to get your aim to a more reliable level we advice you to consider lowering your sens (considerably). Pretty much no one who made the switch from an 'envelope-sized mousepad is almost too big' sensitivity to a more regular one has regretted it.
It's important to find a sensitivity that works for you, however. Once you've got what you want we recommend sticking to it. It's tempting to change things up when you find yourself in a rut but most of what makes a great aimer great is practice. That, and a reliable sensitivity that allows them to make necessary micro adjustments without having their crosshair fly off into the distance while still allowing them to comfortably make flicks and 180 degree turns. Once you've found that sens for you you're good to go!