Tools
Run your own numbers
Free calculators that work entirely in your browser. Nothing you type is sent anywhere, and every one of them shows its working.
Tax and withholding
The ones a spreadsheet makes miserable: thresholds that interact, cliffs that cost four figures for a single dollar, and withholding rates that were never meant to match your bracket.
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2026 figuresTax Threshold Headroom
Find out how much more you can realize this year before you cross a line that costs you.
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2026 figuresRSU Withholding Estimator
See whether the flat 22% withheld on your vesting shares leaves you owing in April.
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2026 figuresQuarterly Estimated Tax
Work out what a freelancer or 1099 earner has to send the IRS, four times a year.
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2026 figuresS-Corp Salary vs Distribution
Find the salary that costs you least — and see what the popular saving figure leaves out.
Housing
Two decisions with more moving parts than anybody can hold in their head, and where the popular answer — buy, and pay it down early — is right often enough to be dangerous.
Retirement timing and limits
How much you are allowed to put in, and when to start taking it out. Both are arithmetic; both are widely got wrong by a margin measured in years or tens of thousands of dollars.
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2026 figuresMega-Backdoor Roth Room
How much after-tax money your 401(k) will still take this year, and what converting it is worth.
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Social Security Break-Even
Claim at 62, at full retirement age, or at 70 — and see how long you have to live for waiting to pay off.
Saving, investing, and debt
Long-run arithmetic. What a balance becomes, what the income side is worth, and the cheapest order to clear what you owe.
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Debt Payoff Calculator
Plan every debt at once and get the cheapest order to clear them in.
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Interest Calculator
Project how a lump sum plus regular contributions grows over time.
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Stock Calculator
Project a share position with both sides of the return: price growth and dividends.