39 free tools live · zero uploads · browser-only
Free calculators for time, money and life's little math problems.
39 calculators running entirely in your browser: convert time zones, estimate a mortgage or loan payment, work out a pregnancy due date, calculate BMI or GPA, and build CSS gradients, shadows, and color palettes for web design.
- Nothing leaves your device
- No account needed
- Free to use
The catalog
39 calculators, grouped by task
Pick a category below, then a tool.
Never lose track of time
Convert between time zones.
Time Zone Converter
Convert a time from one time zone to another.
Countdown to Date
Count down to any future date and time, like a birthday or launch.
Pomodoro Timer
Alternate focus and break intervals using the Pomodoro technique.
World Clock
See the current time in major cities around the world at a glance.
Date Format Converter
Convert a date into ISO, US, EU, long-form, and Unix timestamp formats, free and instant.
Leap Year Checker
Check whether a given year is a leap year, and find the next one.
Do the money math
Estimate mortgage payments and trip fuel cost.
Mortgage Calculator
Estimate your monthly mortgage payment.
Fuel Cost Calculator
Estimate the fuel cost for a trip.
Loan Calculator
Estimate monthly payments and total interest for any type of loan.
Tip Calculator
Calculate tip amount and split the bill between any number of people.
Discount Calculator
Calculate the sale price and savings for any percentage discount.
Salary / Hourly Wage Converter
Convert between annual salary, monthly, weekly, and hourly wage.
Compound Interest Calculator
Project investment growth with compound interest and contributions.
Retirement Savings Calculator
Project your retirement savings balance online, free and instant.
Savings Goal Calculator
Find out how long it will take to reach a savings goal.
Break-Even Calculator
Calculate how many units you need to sell to cover fixed costs.
Paint Calculator
Estimate how much paint you need for a room.
Mark the moments that matter
Due dates, stopwatch and countdown timer.
Pregnancy Due Date Calculator
Use this free due date calculator to estimate a pregnancy due date online.
Stopwatch / Countdown Timer
A simple stopwatch and countdown timer.
BMI Calculator
Calculate Body Mass Index from height and weight, metric or imperial.
Percentage Calculator
Calculate percentages, percentage change, and percentage of a total.
Age Calculator
Calculate exact age in years, months, and days between two dates.
Body Fat Calculator
Estimate body fat percentage from body measurements (US Navy method).
GPA Calculator
Calculate your grade point average from letter grades and credit hours.
Grade Curve Calculator
Curve a set of test scores using common curving methods.
Cooking Measurement Converter
Convert between teaspoons, tablespoons, cups, milliliters, and more.
Unit Converter
Convert between length, weight, temperature, and volume units.
Speed Converter
Convert speed units online for free: mph, km/h, m/s, knots, and ft/s.
Decimal to Fraction Converter
Convert decimals to simplified fractions and fractions to decimals.
Aspect Ratio Calculator
Calculate a simplified aspect ratio and scale dimensions proportionally.
Statistics Calculator
Calculate mean, median, mode, and standard deviation online, free and instant.
Build for the browser
CSS builders, color tools, and layout calculators for the browser.
CSS clamp() Calculator
Generate a fluid CSS clamp() value for responsive font sizes.
CSS Unit Converter
Convert between px, em, rem, pt, and percentage CSS units.
Color Converter
Convert colors between HEX, RGB, and HSL, with a live picker.
Color Contrast Checker
Check whether a text and background color pair meets WCAG standards.
CSS Gradient Generator
Build a linear, radial or conic gradient with any number of colors and copy the CSS or Tailwind class.
Color Palette Generator
Generate a 10-shade color scale from one base color, with WCAG contrast checks for each shade.
CSS Box-Shadow Generator
Design a custom box-shadow visually and copy the CSS.
CSS Border-Radius Generator
Design custom rounded corners for each side and copy the CSS.
Questions
Before you dive in
Are these calculators free?
Yes. All 39 calculator and design tools are completely free with no limits and no account required.
Is my data sent to a server?
No. Every calculation runs entirely in your browser using JavaScript.
Are the mortgage and due date calculators exact?
They are general estimates for planning purposes, not financial or medical advice. Confirm anything significant with a lender or care provider.
Do the math
Open a calculator and get started.
From gradients to mortgages, every calculator runs instantly with nothing saved.