Finance

Compute present and future value of an annuity (ordinary or due).

Estimate beta, alpha and correlation of an asset against a benchmark return series.

Split a bill with tip evenly across a group and show the per-person amount.

Validate the checksum of a Bitcoin address (Base58Check / Bech32 / Bech32m).

Build a level-payment amortization schedule for a fixed-rate bond/loan.

Price a bond from yield, or approximate yield from price.

Compute NOI, cap rate and cash-on-cash return for a rental property.

Approximate US federal capital gains tax (long vs short term).

Compare living costs between major US cities using rough COLI index multipliers.

Identify the payment brand from a card number's IIN and run the Luhn check.

Expected work for a vanity prefix on a Bitcoin (base58) or Ethereum (hex) address.

Project share count and value when reinvesting dividends.

Validate or apply the EIP-55 mixed-case checksum for any Ethereum address.

Compute FIRE number (25× annual spend), years to reach it, and Coast-FIRE amount.

Project years to financial independence at a given savings rate.

Work out the hourly rate a freelancer needs from target income, hours and expenses.

Convert between an hourly wage and an annual/monthly/weekly salary.

Validate an IBAN's country length and ISO 13616 mod-97 checksum.

Convert a past salary into today's dollars using historical US CPI inflation.

Calculate simple interest late fees on an overdue invoice.

Search the active ISO 4217 currency codes, numbers and minor units.

Compare leasing to financing a car (or similar) over the term.

Fetch live cryptocurrency spot prices and 24h change from CoinGecko.

Convert between currencies using live European Central Bank reference rates.

Solve margin, markup and break-even for any pricing or business model.

Compute the maximum peak-to-trough drawdown of an equity curve.

Compute the monthly payment, total interest and amortization for a fixed-rate loan.

After a lump-sum prepayment, find the new monthly payment under a recast.

Compare a lump-sum recast against a full refinance — break-even months and lifetime savings.

Find the months-to-break-even after a refinance and total lifetime savings.

Design a 2-5 column SaaS pricing comparison and export as HTML, JSON or Markdown.

Estimate US federal quarterly self-employment taxes (1040-ES) for the year.

Compute simple ROI, annualised ROI and payback period.

Plan 5-year Roth conversion ladder amounts to fund early retirement gap years.

Estimate how long it takes for an investment to double (72 / rate).

Compute MRR, ARR, NRR, GRR, LTV, CAC, Quick Ratio, Magic Number and Rule of 40.

Calculate sales tax, markup vs margin and retail pricing in one place.

Compute the Sharpe ratio from a series of periodic returns.

Side-by-side: simple, compounded and continuously-compounded growth.

Risk-adjusted return that penalises only downside volatility.

Simulate periodic equal-dollar buys across a price series.

Compute cost basis on a sale using FIFO, LIFO or average-cost methods.

Project a monthly or quarterly stock-option vesting schedule with paper-gain math.

Back-adjust a price series for a forward or reverse stock split.

Estimate US federal income tax on a single-filer 2025 bracket schedule.

Validate a US bank routing number's checksum and identify the Federal Reserve region.

Compute historical Value at Risk and Conditional VaR from a price series.