Read the result correctly
Payback is how long the extra income takes to cover the purchase cost after you buy it. A shorter payback can be useful when your goal is income efficiency. It does not account for new-area access, base space, collection goals, or a future reset.
Time to afford uses your total current income and available Cash. It assumes you save that income without other spending and the rate stays constant. Results compare two independent alternatives; they do not plan buying both upgrades in sequence.
A worked example
These are invented example inputs, not game stats. An upgrade costs 1,000 Cash and changes Animal income from 100 to 150 Cash per second. The gain is 50 Cash per second, so payback is 1,000 ÷ 50 = 20 seconds.
If you have 500 Cash and your total income is 100 per second, saving the remaining 500 takes 5 seconds. At the same constant rates, waiting plus payback takes 25 seconds from now.
What this calculator assumes
- The entered income increase is actually available from the upgrade.
- Before and after values use the same boosts and time unit.
- Income remains constant during the estimate.
- Existing multipliers are already reflected in your values; no extra multipliers are added.
- There is no offline limit, Rebirth reset, price change, or other spending during the estimate.
If the game does not preview the income after an upgrade, leave it unknown rather than guess. A zero or negative income increase has no positive-income payback. A zero earning rate cannot fund an unaffordable purchase in this model.
The formulas
Payback = cost ÷ extra income
Saving time = max(0, cost − Cash) ÷ total current income
Payback and saving time are in seconds or minutes according to your selected rate unit. The tool converts them to a readable duration.
Game mechanics are based on the developer’s Roblox description. Recommendations are editorial reasoning; we have not independently playtested them. See sources & limits.