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Money math, minus the mystery
Free personal-finance calculators for US taxes, housing, retirement, and investing. Run RSU withholding, quarterly estimated tax, rent vs buy, and Social Security break-even in your browser — no signup, and nothing you type is sent anywhere.
28
calculators
$0
to use, forever
0
accounts, ads, paywalls
100%
of it runs in this tab
Tax and withholding
The lines that cost you for one dollar
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.
Tax Threshold Headroom
Find out how much more you can realize this year before you cross a line that costs you.
RSU Withholding Estimator
See whether the flat 22% withheld on your vesting shares leaves you owing in April.
Two-Earner W-4 Fixer
Why a two-income household owes money every April, and the exact figure to put on the form.
Quarterly Estimated Tax
Work out what a freelancer or 1099 earner has to send the IRS, four times a year.
S-Corp Salary vs Distribution
Find the salary that costs you least — and see what the popular saving figure leaves out.
Rental Property Sale Tax
The gain on a rental arrives in two pieces, taxed on two schedules. Price both before you sign.
Job Offer Comparison
Compare two job offers after tax, FICA, housing, and cost of living — not just gross salary.
Kept current
Every bracket, tier, and threshold is dated
9 of these tools depend on figures that change annually. They all read from one file, they all say which year they used, and every export prints it too.
Currently 2026Housing
Arithmetic that runs longer than your patience
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.
Debt Payoff Calculator
Plan every debt at once and get the cheapest order to clear them in.
Interest Calculator
Project how a lump sum plus regular contributions grows over time.
Stock Calculator
Project a share position with both sides of the return: price growth and dividends.
Credit-Card Annual-Fee Calculator
Price a premium card's rewards and perks against what a simple no-fee card would have earned.
I Bond vs HYSA vs CD/T-Bill
Compare three ways to park a lump sum for a known horizon, after tax and after the fine print.
HYSA Emergency Fund Calculator
Turn your own essential expenses into an emergency fund target, and see how long a HYSA takes to get you there.
Auto Loan Calculator
Price a car loan after a trade-in and sales tax — the two things a dealer's monthly payment quote usually obscures.
Loan Calculator
The payment and full amortization schedule for any fixed-rate installment loan — personal, student, or anything else with a term.
Payment Calculator
Know three of loan amount, payment, rate, and term? Solve for the fourth.
Inflation Calculator
What today's dollar amount will cost in the future, and what it's already lost sitting in cash.
Mutual Fund Calculator
Project a fund position and see exactly what its expense ratio costs you by the end.
Compound Interest Calculator
The same nominal rate, compounded annually, monthly, or daily — see exactly how much frequency alone is worth.
Simple Interest Calculator
Interest on the original principal only — the one calculation that never compounds — and what compounding would have added.
ROI Calculator
Total return and annualized return on any investment — a rental, a business, a portfolio — from cost and current value.
More on the way
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Request a toolHow this site behaves
Runs on your laptop
The math happens in this tab. Your figures never leave the browser.
Nothing to sign up for
No account, no email, no free trial quietly counting down.
Takes the answer with you
Every calculator exports a clean PDF, or prints the exact same one.
Nothing personal collected
Anonymous page counts and load times. Never an account, never what you typed.
No ads, no subscriptions, no paywalls. Just the people who use it, keeping it up.
Holdentree is here to make the hard money decisions legible. If something on it saved you an hour — or a genuinely bad decision — there's a coffee fund for that.