A dynamic calculator for task weight can be found here.

The percentage chance of getting assigned a given Slayer task can be calculated using the formula

${\displaystyle {\frac {w}{S}}\times 100\%}$

where ${\displaystyle w}$ is the task's weight and ${\displaystyle S}$ is the sum of all weights for the particular Slayer Master. Note that the weights of all blocked tasks, as well as tasks toggled off have to be subtracted from the sum ${\displaystyle S}$. For Slayer Master/Task Weighting, assuming all possible assignments are available, ${\displaystyle S}$ = .

Preferring a task makes it approximately twice as likely to be assigned, for the first assignment choice, but does not affect the weighting of the second assignment choice provided by a Slayer VIP ticket.[1]

## References

1. ^ Jagex. Mod Rowley's Twitter account. 26 September 2014. (Archived from the original on 28 September 2014.) Mod Rowley: "Preferred Slayer tasks = a silent, second random roll. If either task is on your prefer list, that's what you get (bias towards first roll)... Once normal and prefer roll is decided, [if] you have a VIP ticket, you get the choice between that roll and a third roll."