Calculators that show their work
Free calculators for pay, taxes, dates, school and everyday questions. Every rule is checked against the original source, and every page shows the math and says when it was checked.
New rules for 2027
Quick answers
Money & taxes
- Take-Home Pay CalculatorSalary to paycheck after taxes, for every state
- Paycheck CalculatorHourly or salary, per pay period, by state
- Salary CalculatorAnnual, monthly, weekly, daily and hourly pay
- Hourly to Salary CalculatorAn hourly wage as a yearly salary, and back
- Income Tax Calculator2026 federal income tax with brackets shown
- Sales Tax CalculatorAdd or remove sales tax, with state rates
- Inflation CalculatorWhat a dollar from any year since 1913 is worth now
- Auto Loan CalculatorCar payment, total interest, trade-in and tax
- Loan CalculatorPayment and amortization for any fixed-rate loan
- CD CalculatorWhat a certificate of deposit earns by maturity
- 401(k) CalculatorYour balance at retirement with the 2026 limits
- Roth IRA CalculatorHow much you may put in, and what it grows to
Dates & time
- Days From Today CalculatorAny number of days, weeks or months from today
- Date CalculatorAdd or subtract days, weeks, months or years
- Days CalculatorDays, weeks and business days between two dates
- Hours CalculatorHours worked from clock-in to clock-out, minus breaks
- Time Card CalculatorA week of shifts to total hours and pay
- Time CalculatorAdd or subtract hours and minutes, or the time between two times
- Age CalculatorExact age in years, months and days
Percent & grades
Everyday
- Snow Day CalculatorThe chance school closes, from the National Weather Service forecast
- Random Number GeneratorFair random numbers, with or without repeats
- Dice RollerRoll any number of dice with any number of sides
- Concrete CalculatorCubic yards and bags for slabs, footings and posts
- Sleep CalculatorWhen to wake up or go to bed, in full sleep cycles
How we build
Checked against the source
Tax brackets from the IRS, prices from the Bureau of Labor Statistics, rules from the law itself. Each page lists its sources and the date we last checked them.
The math, line by line
Results come with the steps that lead to them, so you can follow every number and catch anything that doesn't fit your situation.
Honest about limits
A calculator is an estimate, not advice. Where a rule is still a proposal, or a form isn't out yet, the page says so. How we check