Personal Investing Calculators

Enter your crypto purchases and the price today, and see your average cost, the units you hold, your gain or loss and how much of it is on purchases held more than one year, and compare selling a share of your units first in, first out, last in, first out or highest cost first. Then simulate a fixed purchase every 1, 2 or 4 weeks across 100 weekly price paths inside a seeded, reproducible workbook, and see the range of the plan's value by week and the chance that it ends below what it put in. Gains and holding periods, not the tax on them. Estimates for education, not advice.

Simulate 100 market futures for a retirement plan whose mix of equities, bonds and cash follows a glide path by age, inside a seeded, reproducible workbook, and see the share of futures in which the money lasts to the end age, the equity share today and the spread of balances by age. Each year is drawn with the average return and volatility of that year's mix, less fees; contributions and withdrawals rise with inflation. Estimates for education, not advice.

Simulate 100 market futures for yearly contributions to a 529 plan or an HSA inside a seeded, reproducible workbook, and see the range of balances when the money is withdrawn, the tax the contributions save, and how far the account comes out ahead, after tax, of an ordinary taxable account that costs you the same each year. Tax is shown at contribution, on growth and at withdrawal for both. Estimates for education, not advice.

Find the Kelly bet, the share of the bankroll that makes it grow fastest over many bets, from your chance of winning and the odds, size your bet as a share of it, and simulate 100 seeded sequences of 200 bets at full, half and quarter Kelly and at your size inside a reproducible workbook: see how often each falls further from a peak than you can accept and how the bankroll spreads. Estimates for education, not advice.

Simulate 100 monthly price paths for a position bought partly with a margin loan inside a seeded, reproducible workbook, and see the chance of a margin call within the horizon, how far the value can fall today before a call, the share price that triggers one, the leverage and what the loan costs a year, with a price fall, no change and a rise compared with and without the loan. Margin is checked at each month end. Estimates for education, not advice.

Simulate 100 market futures for a retirement plan inside a seeded, reproducible workbook and see the share in which the money lasts, the spread of balances year by year, when failures happen, and how a smaller withdrawal, a later start or lower volatility moves the odds. Returns are lognormal with the average and volatility you enter, less fees; withdrawals rise with inflation. Estimates for education, not advice.

Work out the cash flow, cap rate, cash-on-cash return, debt service coverage and return on the money invested of one rental property, before income tax, then simulate 100 futures of rent growth, vacancy and appreciation inside a seeded, reproducible workbook to see the spread of returns, the share returning less than the mortgage rate and the share with a year of negative cash flow. Estimates for education, not advice.