Compare API costs across 20+ models including GPT-4, Claude, and Gemini side by side.

Calculate monthly payments, total interest, and get a full amortization schedule instantly.

Calculate your BMR, TDEE, and daily macro targets for weight loss, maintenance, or muscle gain.

Estimate your true take-home pay after federal, state, FICA taxes and pre-tax deductions like 401(k).

Calculate the hourly rate you need to charge to cover taxes, expenses, and hit your income goals.

Calculate the exact late fee to add to an overdue invoice using flat fee, monthly percentage, or daily interest.

Estimate your SE tax, federal income tax, state tax, and quarterly payments for 2025.

See which pays more after taxes, benefits, SE tax, QBI deduction, and break-even rate.

Enter your loan amount, interest rate, term, and expected revenue to calculate ROI and net profit.

Analyze any rental deal — cash flow, cap rate, NOI, cash-on-cash return, DSCR, and 5-year projections.

Calculate how much you could save in taxes by electing S-Corp status, including break-even profit level.

Estimate your one-rep max using the Epley formula and get training weights for every intensity zone.

Calculate your daily protein, carbohydrate, and fat targets based on your calorie goal.

Estimate body fat with the U.S. Navy method or a BMI-based estimate, plus lean mass and your healthy range.

Work out what to send the IRS each quarter, when it is due, and which safe harbor keeps you clear of the underpayment penalty.