How to use this calculator
Calculate expected attempts and attempts needed for common success probabilities.
How the calculation works
- Enter the design assumptions for the system you are balancing.
- Tool2Do calculates a deterministic table or result from the displayed method.
- Use export options only where the output is reusable game data.
Formula
Attempts for target chance = log(1 - target) / log(1 - success chance).
Example
A 2% success chance takes about 35 attempts for a 50% chance and 114 attempts for 90%.
Understanding your result
Use the output as a practical starting point, then review it before using it in an important workflow.
Assumptions and limitations
- Calculations run locally in your browser.
- These are balancing helpers, not universal game design rules.
- Do not paste private production telemetry or player data.
Frequently asked questions
Does this require an account?
No. The core tool works without creating a Tool2Do account.
Is my input included in share links or analytics?
No. Tool2Do share actions use the tool page URL and safe metadata, not private values or uploaded files.