This calculator is arithmetic on a table, not a live mixer. Enter quantities from your own Break your Bones ☠️ session. It will not click the shop.
Drop probability
Material Spin hit chance
Estimates the chance of seeing a spin result at least once. Type the percent printed for that material. Glass is published at 6 percent, which is only the sample default. The published chances do not add up to 100 percent, and this form assumes independent spins. That may not be how the in-game wheel is coded.
Chance of at least one success = 1 − (1 − chance per attempt) raised to the number of attempts.
Default 6 matches the published Glass chance. Replace it with the chance of the material you care about. Do not treat the result as an official drop rate.
Upgrade payback
Cash purchase payback
Compares a Cash purchase with the extra Cash you personally measure per run. The sample cost of 800 is the published Mutant price. The sample extra of 100 Cash per run is not a measured Mutant payout. Replace both numbers before you trust the result. Minute length is your own run time.
Payback cycles = upgrade cost ÷ extra profit per cycle, rounded up.
800 is Mutant's published price so the form is not empty. 100 extra Cash and 1 minute are placeholders, not game data.
