Free online calculators, with the working shown
Statistics, scientific, percentage, fractions, chemistry, grades and everyday sums — each one shows the formula and the steps, so you can check the answer or use it for homework. No signup.
Built and checked by Sunil Arora. How we build and test our calculators
Most used
Calculators by subject
Browse all calculators →Money calculators (US, 2026)
Money guidesPaychecks, income tax, retirement, student loans and home buying, using 2026 federal and state rules.
- Federal & State Income Tax Calculator
- 1099 Quarterly Tax Calculator
- Take-Home Pay Calculator
- Salary to Hourly Converter
- 401(k) Calculator with Employer Match
- Roth vs Traditional IRA Calculator
- Student Loan Payoff Calculator
- Mortgage Affordability Calculator
- Rent vs Buy Calculator
- Mortgage Payment Calculator
- ACA Health Insurance Subsidy Calculator
- 529 College Savings Calculator
Frequently asked questions
What is CalciTools?
CalciTools is a free set of online calculators for math, statistics, science, school grades and everyday sums — plus US paycheck and tax tools. Most calculators show the formula and the working, not just the answer, so you can check it or use it for homework.
Do the calculators show the steps?
Yes, where it helps. The statistics calculator walks through the mean, variance and standard deviation line by line, the prime checker shows the trial division and the prime factorization, and the math tools show the formula they use.
Do you store the numbers I enter?
No. Calculations happen on your device and nothing you type is sent to our servers or to analytics. Some calculators put your inputs in the page address so you can bookmark or share a result.
Is CalciTools free?
Yes. Every calculator is free with no account or signup.
Can I put a calculator on my own website or class page?
Yes. Many calculators have an embed code at the bottom of the page — copy it into your site, blog or learning platform and the calculator works there for free.