Project how an investment grows over time with optional recurring contributions and compounding. Returns the future value, total contributed, interest earned, an inflation-adjusted 'real' value, and a year-by-year schedule. Use this to answer 'how much will my investing turn into?'.

Build a full amortization schedule for a loan or mortgage. Supports recurring extra principal payments and reports the interest those extra payments save plus the new payoff date. Use this for mortgages, auto loans, or any fixed-rate installment loan.

Plan how to get out of debt fastest. Simulates month-by-month payoff of multiple debts using the avalanche (highest interest first) and/or snowball (smallest balance first) methods, rolling freed-up payments onto the next target. Reports months to debt-free, total interest, and which strategy wins.

Compute your FIRE number (the portfolio needed to live off withdrawals), your savings rate, and how many years until you reach financial independence given your income, expenses, current investments, and expected real return. Also reports lean-FIRE and fat-FIRE targets.

Calculate the hourly rate a freelancer or consultant must charge to actually hit a target take-home income, correctly accounting for non-billable time, vacation, taxes, and business expenses. Stops you from under-charging by using your old salary divided by 2080.

Find the price that maximizes profit for a product or service. Fits a linear demand curve to your observed price/quantity points, derives the optimal price from unit economics, and returns a transparent price sweep. Also reports the revenue-maximizing price for growth strategies.

Compare multiple investments or business opportunities on the metrics that matter: ROI, payback period, NPV, and IRR. Each opportunity is a series of cash flows (period 0 is usually the negative initial outlay). Tells you which option creates the most value.

Estimate income tax under a progressive bracket schedule. Defaults to US 2024 single-filer federal brackets but accepts any custom brackets (any country/year). Reports total tax, after-tax income, the per-bracket breakdown, and your effective vs marginal rate.

Analyze a monthly budget against the 50/30/20 rule (needs/wants/savings). Surfaces overspending, unallocated money, your actual split vs the target, and concrete recommendations to raise your savings rate.

Audit recurring subscriptions: annualize every line, compute cost-per-use, and flag low-value or rarely used services as candidates to cut — quantifying exactly how much money you can recover per year.

Rank side-hustle ideas by risk-adjusted effective hourly value, accounting for startup cost, ramp time, ongoing costs, hours, and probability of success. Turns 'which side hustle should I start?' into a numbers-driven decision.