user2785: I've been trying out the FIDE Online Arena; while I've found a lot of marketing, I find very little useful documentation (possibly because the software is new).
FIDE Online Arena has four different Elos: bullet, blitz, rapid, and unmonitored.
Q: What specifically determines bullet, blitz, rapid, and unmonitored time controls?

user12629: For the FIDE Online Arena, only specific time controls can be rated. For example, you can play a rated 5 minute or 10 minute blitz game, but if you play a 7 minute game it will always be unrated.
According to the FIDE Online Arena Rating Regulations, the ratable time controls are as follows:

2.3     Rated games use the following predetermined time controls:
2.3.1   For rapid chess: 15m, 25m, 45m, 10m + 10s, 15m + 10s, 25m + 10s, 45m + 10s
2.3.2   For blitz chess: 3m, 5m, 10m, 3m + 2s, 3m + 3s, 5m + 3s
2.3.3   For bullet chess: 1m, 2m, 1m + 1s, 1m + 2s


user1516: I think all the above said is true - but i think most online chess platforms differ a little from the fide definition: 
FIDE takes 
Basetime + 60 * increment 

for their calculation and then says 

Bullet < 3 minutes 
Blitz <= 10 minutes 
Rapid <= 60 minutes

While most other platforms take 
Basetime + 40 * increment

as a base for their calculation - so the very weird timecontrol 
0 minutes + 4 seconds per move is usually considered Bullet

user3798: Yes, exactly. Blitz: 3-5 minutes per side, usually no increment. Bullet: 1 or 2 minutes per side. Rapid: 15 to 60 minutes per player. sometimes with a small time increment per move for example 10 seconds.
For me personally, i like it so far because as far as i know, FIDE online arena is one of the Premium Chess members which i suppose all of National Federations are also members of Premium Chess. And its very interesting to play with people from world federations. The interface indeed can be improved a lot, but i do like their design and website.

user-1: According to FIDE:
Blitz: <= 10 minutes
Rapid: > 10 minutes and <= 60 minutes
Source: http://www.fide.com/component/handbook/?id=171&view=article (See appendices)

According to Wikipedia and many online chess platforms:
Bullet: < 3 minutes
Blitz: >= 3 minutes and < 10 minutes
Rapid: > 10 minutes and <= 60 minutes
Source: https://en.wikipedia.org/wiki/Fast_chess

2785: <p>I've been trying out the <a href="http://arena.myfide.net/" rel="noreferrer">FIDE Online Arena</a>; while I've found a lot of marketing, I find very little useful documentation (possibly because the software is new).</p>

<p>FIDE Online Arena has four different Elos: bullet, blitz, rapid, and unmonitored.</p>

<p>Q: What specifically determines bullet, blitz, rapid, and unmonitored time controls?</p>
 12629: <p>For the FIDE Online Arena, only <em>specific</em> time controls can be rated. For example, you can play a rated 5 minute or 10 minute blitz game, but if you play a 7 minute game it will always be unrated.</p>
<p>According to the <a href="https://handbook.fide.com/chapter/B11FOARatingRegulations" rel="nofollow noreferrer">FIDE Online Arena Rating Regulations</a>, the ratable time controls are as follows:</p>
<blockquote>
<p>2.3     Rated games use the following predetermined time controls:<br />
2.3.1   For rapid chess: 15m, 25m, 45m, 10m + 10s, 15m + 10s, 25m + 10s, 45m + 10s<br />
2.3.2   For blitz chess: 3m, 5m, 10m, 3m + 2s, 3m + 3s, 5m + 3s<br />
2.3.3   For bullet chess: 1m, 2m, 1m + 1s, 1m + 2s</p>
</blockquote>
 1516: <p>I think all the above said is true - but i think most online chess platforms differ a little from the fide definition: </p>

<p>FIDE takes </p>

<pre><code>Basetime + 60 * increment 
</code></pre>

<p>for their calculation and then says </p>

<ul>
<li>Bullet &lt; 3 minutes </li>
<li>Blitz &lt;= 10 minutes </li>
<li>Rapid &lt;= 60 minutes</li>
</ul>

<p>While most other platforms take </p>

<pre><code>Basetime + 40 * increment
</code></pre>

<p>as a base for their calculation - so the very weird timecontrol 
0 minutes + 4 seconds per move is usually considered Bullet</p>
 3798: <p>Yes, exactly. Blitz: 3-5 minutes per side, usually no increment. Bullet: 1 or 2 minutes per side. Rapid: 15 to 60 minutes per player. sometimes with a small time increment per move for example 10 seconds.</p>

<p>For me personally, i like it so far because as far as i know, FIDE online arena is one of the Premium Chess members which i suppose all of National Federations are also members of Premium Chess. And its very interesting to play with people from world federations. The interface indeed can be improved a lot, but i do like their design and website.</p>
 -1: <p>According to FIDE:</p>

<p>Blitz: &lt;= 10 minutes</p>

<p>Rapid: > 10 minutes and &lt;= 60 minutes</p>

<p>Source: <a href="http://www.fide.com/component/handbook/?id=171&amp;view=article" rel="noreferrer">http://www.fide.com/component/handbook/?id=171&amp;view=article</a> (See appendices)</p>

<hr>

<p>According to Wikipedia and <strong>many</strong> online chess platforms:</p>

<p>Bullet: &lt; 3 minutes</p>

<p>Blitz: >= 3 minutes and &lt; 10 minutes</p>

<p>Rapid: > 10 minutes and &lt;= 60 minutes</p>

<p>Source: <a href="https://en.wikipedia.org/wiki/Fast_chess" rel="noreferrer">https://en.wikipedia.org/wiki/Fast_chess</a></p>
