Enter the target number you need to roll on a D20 die into the calculator to determine the probability of rolling that number or higher.
D20 Probability Formula
The following formula is used to calculate the probability of rolling a target number or higher on a D20 die.
P = ((21 - T) / 20) * 100
Variables:
- P is the probability (%) of rolling the target number or higher
- T is the target number (1-20) on the D20 die
To calculate the probability, subtract the target number from 21, divide by 20, and then multiply by 100 to get the percentage.
What is D20 Probability?
D20 probability refers to the chance of rolling a specific number or higher on a 20-sided die, commonly used in tabletop role-playing games like Dungeons & Dragons. Understanding these probabilities can help players make strategic decisions during gameplay.
How to Calculate D20 Probability?
The following steps outline how to calculate the D20 Probability.
- First, determine the target number (T) you need to roll on the D20 die.
- Next, use the formula P = ((21 - T) / 20) * 100.
- Finally, calculate the probability (P) of rolling the target number or higher.
- After inserting the target number and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Target number (T) = 15
Using the formula P = ((21 - T) / 20) * 100, we find that the probability of rolling a 15 or higher on a D20 die is 30%.