Best debt payoff calculator for solo founders

There are roughly 30-50 general debt payoff calculators in the market (Undebt, Debt.com tools, mint-adjacent products), but almost none are purpose-built for solo founders managing business debt, personal debt, and variable income simultaneously. The common failures are treating debt payoff as a linear personal finance problem when founders operate in nonlinear territory: some months you're flush, others you're reinvesting everything. Most existing tools also ignore the psychological layer—founders need to see how aggressively they can pay down debt without killing their business runway or growth. The real gap is a calculator that models debt payoff against three founder-specific variables: (1) variable monthly revenue, (2) forced business reinvestment percentages, and (3) personal burn rate. A new entrant should focus on a lightweight, scenario-based tool that lets founders model 3-5 different payoff strategies in parallel, show the founder which strategy maximizes both debt elimination and business health, and integrate loose connections to basic tax implications for business debt vs. personal debt. The market is underserved but not untouched—this is a $200-500K revenue niche for a focused shipper, not a unicorn play.