Speed
Speed is simply how fast a character can move in a given amount of time. There are five types of speed used for VS purposes: Attack Speed, Combat Speed, Reaction Speed, Travel Speed, and Flight Speed. The term "Speed" normally refers to Combat Speed.
Attack Speed
The speed at which an attack moves. For example, X character is hypersonic, but he can do an attack that is a natural beam of light, the speed for the attack is different from the speed of the user, hence the attack would be lightspeed even if its user isn't.
Combat Speed
The speed at which a character can fight.
Reaction Speed
Reaction speed is the speed at which a character can react to an event or action. This usually only grants a short movement upon reaction, whereas several movements at the same speed switch it to combat speed.
For example, let's say that character A shoots at character B with a gun and character B dodges. That is reaction speed. Keep in mind, sometimes a person aim dodges and it is not as good of a feat.
As another example, let's say that character A uses a minigun on character B, but the minigun takes a second or two to charge up and Character B sees this. If Character B dodges it is considered aim dodging since he/she knew that the attack was going to happen.
Reaction speed is reacting to an attack that you don't know is going to happen, or at a very close range. The reaction speed of a character also tends to be higher than its movement speed.
Travel Speed
The speed at which a character or object can move by running, or through similar means that do not involve flight or teleportation.
Flight Speed
The speed at which a character or object flies a certain distance, like going from the earth to the sun for example.
High flight speed logically requires similar reaction speed in order to manoeuvre when approaching different objects.
However, certain franchises, such as Marvel Comics (and DC Comics or Image Comics, which follow the same conventions), make a great distinction between regular movement speed and flight speed.
As such, we have generally assumed that the characters' regular reaction or combat speeds are roughly equivalent to their flight speeds, unless this is clearly contradicted.
Conversion
You can use this calculator to convert from one speed unit to another.
Speed Levels
Below Average Human (0-5 m/s)
Normal Human (5-7.7 m/s)
Athletic Human (7.7-9.8 m/s)
Peak Human (9.8-12.51 m/s)
Superhuman (12.51-34.3 m/s)
Subsonic (Faster than the Eye) (Mach 0.1-0.5) (34.3-171.5 m/s or 76.7-383.6 mph)
Subsonic+ (Mach 0.5-0.9) (171.5-308.7 m/s)
Transonic (Mach 0.9-1.1) (308.7-377.3 m/s)
Supersonic (Mach 1.1-2.5)
Supersonic+ (Mach 2.5-5)
Hypersonic (Mach 5-10)
Hypersonic+ (Mach 10-25)
High Hypersonic (Mach 25-50)
High Hypersonic+ (Mach 50-100)
Massively Hypersonic (Mach 100-1000)
Massively Hypersonic+ (Mach 1000-8810.2)
Sub-Relativistic (1%-5% SoL)
Sub-Relativistic+ (5%-10% SoL)
Relativistic (10%-50% SoL)
Relativistic+ (50%-100% SoL)
Speed of Light
FTL (x1-10 Speed of Light)
FTL+ (x10-100 Speed of Light)
Massively FTL (x100-1000 Speed of Light)
Massively FTL+ (x1000+ Speed of Light)
Infinite Speed (Able to move indefinitely while time literally stands still, or to travel anywhere instantly. Teleportation does not count. For further information, see note 4 below.)
Immeasurable (Movement beyond linear time. This is why the speed cannot be measured. Given that S = D/T, if T is undefined the speed formula cannot be applied. This is the same reason why multiple temporal dimensions also grant immeasurable speed. For further information, see note 5 below.)
Irrelevant (Characters beyond, and qualitatively superior to, the concepts of dimensions of time and space themselves. Meaning: Tier 1-A and above.)
Other
Omnipresent (This is technically a state of being, rather than a speed, but has consequences for combat similar to that of a speed statistic. For practical comparisons, each case requires more detailed consideration.)
Notes
Note 1:
The speed tiers used have intersecting limits, and this may be confusing to some members. The divisions are made based on Exclusive Form grouping, in which the true lower limit is the given lower limit and the true upper limit is just short of the given upper limit.
Examples:
1) Mach 10 is Hypersonic+, not Hypersonic.
2) Mach 100 is Massively Hypersonic, not High Hypersonic+.
Note 2:
Kindly note that MFTL+ is a very broad category which starts from 1000x Speed of Light up to infinity. As such, MFTL+ characters need not be even remotely on a similar level of speed. In fact, the difference may be as great as the magnitude of difference between MFTL and regular human level.
In conclusion, one MFTL+ character can speed blitz another MFTL+ character, and assuming otherwise without a logical reason is fallacious.
Note 3:
While Omnipresence is, strictly speaking, not speed, it is listed as a speed statistic due to behaving in combat similarly to how normal speed would. For example, a being that is omnipresent within 3-D space would win every race against an opponent with normal speed, due to already being at the goal by the time the race starts. In addition, an attack from an omnipresent being is unavoidable with normal speed due to the attack being in every location in the universe at once.
A being that is not only omnipresent throughout space, but also time, would also be able to react to every attack from a being with normal speed before the opponent would even begin to throw the attack. This is the case because such a being would exist throughout all of time, experiencing past, presence and future at once while not being bound to the normal flow of time.
Omnipresence must be specified in conjunction with the scale. Because omnipresence within a single 3+1-D universe (aka a regular 4-D space-time continuum) does not mean anything to regular life forms in higher dimensions of time and space (which might be larger and more complex than this universe).
A character that is omnipresent within a certain space is not necessarily swifter than all non-omnipresent beings. In addition, if a certain character is omnipresent on a universal scale, it is not a relevant advantage during a match-up against a character that can destroy universes.
Note 4:
Characters who showcase the ability to move freely and naturally in a timeless void may qualify for an infinite speed rating so long as it is not a huge Outlier or Plot-Induced Stupidity or Inconsistency. Such feats will have to be very carefully evaluated on a case-by-case basis.
Note 5:
Characters that are able to move backwards and forwards through time by movement alone qualify for immeasurable speed. However, due to general inconsistencies, and the fact that several fictions grant this ability to any character able to move FTL, they may be assigned an additional, independent, speed rating for the ability. This should preferably be evaluated on a case-by-case basis.
The difference between infinite and immeasurable is that the former can go everywhere instantly, whereas the latter can go everywhere and everywhen.