Free Online Tools That Just Work
Accurate calculators and converters with instant results. No sign-up, no downloads, no nonsense — pick a tool below and get your answer in seconds.
Paycheck Tax Calculator
Estimate your take-home pay after federal and state taxes. Updated for 2026 brackets.
Mortgage Calculator
Calculate monthly payments, total interest, and the true cost of your home loan.
Unit Converter
Convert length, weight, temperature, volume and more between metric and imperial.
Age Calculator
Find your exact age in years, months and days — plus days until your next birthday.
BMI Calculator
Check your Body Mass Index instantly with metric or imperial units.
All Tools →
Browse the full collection: finance, math, health and utilities.
Why QuickTools?
Every tool on this site runs entirely in your browser — your numbers never leave your device. Results are instant, the math is transparent, and there is nothing to install.
How to use these calculators
Open any tool, enter your numbers, and hit calculate. Each page explains the formula it uses and answers the most common questions, so you always know where a number comes from.
Frequently asked questions
Are these tools really free?
Yes. Every calculator and converter on QuickTools is free to use with no account required. The site is supported by advertising.
Is my data sent anywhere?
No. All calculations happen locally in your browser with JavaScript. Nothing you type is uploaded or stored.
How accurate are the calculators?
They use standard published formulas (IRS tax brackets, the standard mortgage amortization formula, WHO BMI categories). Tax tools are estimates — for filing decisions, consult a tax professional.
Do you have state-specific paycheck calculators?
Yes — we have a dedicated calculator for all 50 states plus DC. Find your state here.
Can I suggest a new tool?
We're adding new tools every week based on what people search for. The full list lives on the All Tools page.