Saving & Spending Calculators

Estimate the year buying a home becomes cheaper than renting after mortgage interest, maintenance, selling costs, and cash opportunity cost.

Calculate the exact month your cash runs out. Crisis toggle models a worst-case scenario with revenue zeroed.

How many months of debt service survive an unexpected shock expense. Critical warning under 3 months.

The exact month when a monthly subscription overtakes a one-time lifetime purchase. Opportunity-cost toggle included.

The exact date a side-hustle can sustainably replace a primary salary, factoring self-employment tax and benefits loss.

Should you hire a human at $X/hr or pay $Y/mo for a SaaS/automation stack? Efficiency bar comparison.

Is your time worth more than the professional quote? Balance-scale verdict with DIY cost vs outsourcing.

When does a $2k cloud bill justify an $8k rack? Crossover math with depreciation, electricity, and uptime risk.

The absolute minimum hourly rate to match a corporate salary after self-employment tax, benefits, and non-billable time.

What this $10k would be worth in 10, 20, or 30 years if invested instead. Compound-growth opportunity-cost filter.

Quantify the compounding hours to fix a shortcut as the codebase grows on top of it. Maintenance heatmap.

Estimate whether the next hire raises or lowers revenue per employee after management time and ramp-up.

Most calories per dollar spent — survival math for when the food budget is hard-capped.

What DoorDash or Uber actually pays after IRS mileage depreciation — real hourly vs the minimum wage floor.

When you can't pay everything, which bill first? Weighted ranking by service-cutoff risk and late-fee pain.

Turn abstinence from a habit into dollars saved toward something you actually need.

Weighed social ROI — does the connection payoff beat the transit, cost, and energy tax of leaving the house?

Compute the true APR of a payday loan, pawn redemption, or cash advance — with a predatory heatmap from fair to extortionate.

Estimate when extra work hours stop being worth the fatigue cost from lost sleep.

Rank food by kilocalories per dollar and convert grocery spend into days of biological uptime at a 2,000 kcal baseline.

Prioritize essential bills first when there is not enough cash to pay everything.

Compare gig earnings with the estimated vehicle wear created by the miles driven.

Compare the benefit of a social plan against the time, energy, and money it costs.

Boots-theory math: cheap-vs-quality cost per day over a 5-year horizon, with an injustice-gap total.

Real hourly wage after transit time (uncompensated labor) and transit cost eat into shift earnings.

Should you sell an asset to avoid a late fee? Replacement penalty vs fee avoided — equity loss meter.

What percent of your labor pays for the sanity premium of living alone vs with a roommate? Peace-vs-capital slider.

Calculate your monthly mortgage payment with taxes, insurance, HOA, and PMI. See total interest and what each 1% rate change really costs.

See how extra payments change your payoff date and total interest. Monthly, annual, or one-time — all scenarios side by side.

See when you'll hit your savings target and how extra contributions or growth change the timeline.

Calculate the sale price and savings from any percent-off discount.

Calculate tips and split a restaurant bill. Includes 15/18/20% side-by-side comparison.

Calculate markup percent, selling price, and gross profit from cost. Shows how a price change affects the markup.

Calculate gross margin, profit, and the price required to hit a target margin. Shows equivalent markup alongside.

Convert between cost, price, markup, and margin. Shows profit, markup %, and margin % from any two inputs.

Calculate how many units you must sell to cover fixed costs — break-even quantity and revenue.

Calculate percentages: what is X% of Y, X is what % of Y, and % change.