Free, fast tools for everyday life
No account required. No data collected. All calculations happen directly in your browser.
QuicklyTools is a growing collection of free online calculators for the everyday questions money, health, and time keep throwing at you. Estimate your take-home pay after taxes, work out a loan payment, check your BMI, find your running pace, calculate a pregnancy due date, split a restaurant bill, or convert between units — each one is built to give you a clear answer in seconds.
There are no accounts, no pop-ups, and no tracking of your inputs. Every calculation runs entirely in your browser, so the numbers you type never leave your device. And when you want to understand the math behind a result, our in-depth guides explain how each tool works in plain English.
Choose a tool
Paycheck Calculator
Estimate your take-home pay after federal tax, state tax, Social Security, and Medicare.
Use ToolShift Work Schedule
Generate a 4-week calendar for Panama, Pitman, 4-on-4-off, and DuPont rotations.
Use ToolRunning Pace Calculator
Calculate pace, predict finish times, and forecast race results using the Riegel formula.
Use ToolPregnancy Calculator
Find your due date, current week, trimester milestones, and fertile window.
Use ToolColor Contrast Checker
Check WCAG AA/AAA contrast ratios for text and get suggested accessible color alternatives.
Use ToolLoan Calculator
Calculate monthly payments and total interest for any loan or mortgage.
Use ToolTip Calculator
Split the bill and calculate tip for any party size.
Use ToolBMI Calculator
Calculate your Body Mass Index and healthy weight range.
Use ToolUnit Converter
Convert length, weight, temperature, and volume between any units.
Use ToolAge Calculator
Find your exact age in years, months, and days — or the difference between any two dates.
Use ToolWhy QuicklyTools?
Instant results
No loading spinners. Results appear as you type.
Private by default
Everything runs in your browser. Nothing leaves your device.
Works everywhere
Fully responsive. Works great on phone, tablet, and desktop.
From our guides
View all →Training for Your First 5K, 10K, or Half Marathon
You don't need to run fast to finish your first race — you need to run consistently. Here's how much to train, why most miles should feel easy, and how to pick a realistic goal.
How to Adjust Your W-4 So Your Paycheck Withholding Is Right
A big refund means you lent the government money for free. Here's how the W-4 controls your withholding and how to adjust it so your paycheck is right all year.
How Age Is Calculated: Leap Years, Month Math, and Date Differences
Your exact age isn't days ÷ 365. Here's how the years-months-days breakdown really works, how leap years fit in, and how to measure the gap between any two dates.