Progress Celebration Planner Calculator

Total Celebration Budget is Total Debt times Celebration Budget %, then split unevenly across four milestones: 15% of that budget at the 25%-paid mark, 20% at halfway, 25% at the 75% mark, and 40% reserved for the final debt-free celebration (lines 21-27). The calculator then runs two separate month-by-month payoff simulations at the same payment and rate — one with no celebration spending, one where each milestone's celebration dollars get added back onto the remaining balance the moment you cross that milestone (lines 32-66). The debt-free celebration budget is the one exception: because it's spent only after the debt hits zero, it never gets added back into the simulation and so adds no extra months or interest on its own.

Total Debt has the largest effect on Extra Interest From Celebrations of any single input, ahead of Monthly Payment, Avg Interest Rate, and Celebration Budget %, because it drives both the size of each celebration deposit and the size of the balance that interest keeps accruing on. Budget Reasonable checks whether the average celebration (Total Celebration Budget divided evenly by four, which works out to the same number as averaging the four uneven milestone amounts) stays under 5% of Monthly Income (lines 74-78); push Celebration Budget % high enough and it flips from reasonable to not, independent of Celebration Tier, which tracks the same average dollar amount against flat $25/$100/$300 breakpoints instead (lines 82-86). This tool doesn't verify that celebration spending actually happens or stays within its own budget.