- Internal Item ID: 3099 (Desktop, Console and Mobile versions)
The Stopwatch is an informational accessory that displays the player's current movement speed in miles per hour, e.g. "34 mph". The Stopwatch can be purchased from the Traveling Merchant for 5 GC.
The Stopwatch is one of the three parts necessary to make the Goblin Tech, with the others being the Metal Detector and the DPS Meter, and as such is a required ingredient in crafting the Shellphone.
- Unlike most accessories, informational accessories such as the Stopwatch do not need to be equipped in an accessory slot. The Stopwatch may be carried in the player's inventory without loss of functionality, unless equipped to a social slot. Additionally, the info it provides will be shared with nearby players of the same team in multiplayer. Keep in mind modifiers will no longer apply to the player when not equipped.
- The conversion factor between miles/hour and tiles/second in Terraria is 11/15 (0.7333...), and conversely, 15/11 (1.363636...) between tiles/second and miles/hour. For example, the Minecart's top speed is 66 mph, which is equal to 48.4 tiles/second.
- This is taken from Terraria's source code, where the player's internal pixels-per-tick velocity is multiplied by
216000/42240 (hard-coded) to get the miles-per-hour velocity for display. The numerator of this fraction represents 1 hour in ticks: 60 ticks in a second multiplied by 3600 seconds in an hour = 216000 ticks. The denominator represents 1 mile in pixels: 16 pixels in a tile multiplied by 1/2 tile in a foot multiplied by 5280 feet in a mile = 42240 pixels. Flipping the fraction gets the conversion factor between miles per hour and pixels per tick:
42240/216000. 1 pixel per tick is equal to 1/16 tiles (16 pixels in a tile) per 1/60 seconds (60 ticks in a second), hence the conversion factor between miles per hour and tiles per second is
(42240/16)/(216000/60) = 2640/3600 = 11/15.
- When riding in a Minecart or running, the Stopwatch's display only represents horizontal speed. When midair (jumping, flying, etc.), the displayed value is the total velocity in any direction.
- When moving horizontally along a Rope or Hoik, the Stopwatch will display "0 mph" regardless of how fast the player is moving.
- ↑ A tick is a time unit countable by the software. Most of Terraria's updating logic happens every tick. A tick has the length of 1/60th of a second, hence there are 60 ticks in a second and 3600 ticks in a minute.
- ↑ Information taken from the Desktop 22.214.171.124 source code, method
Terraria.Main.cs. There may be inaccuracies, as the current Desktop version is 126.96.36.199.
- ↑ 3.0 3.1 1 tick = 1/60th of a second