Tip Calculator
Calculate the tip and split a bill between people.
Age Calculator
Your exact age in years, months, and days.
Date Calculator
Days between two dates, or add/subtract days from a date.
Time Duration Calculator
How long between two times — in hours and minutes.
Hours Calculator
Sum hours worked across multiple shifts.
GPA Calculator
Weighted GPA from grades and credit hours.
Grade Calculator
Final course grade from assignment weights and scores.
Concrete Calculator
Cubic yards of concrete for a slab.
Tire Size Calculator
Outer diameter, sidewall height, and circumference from a tire code.
Love Calculator
A totally unscientific compatibility score from two names.
Fuel Cost Calculator
How much a trip costs in gas.
Gas Mileage Calculator
MPG or km/L from distance and fuel used.
Length Converter
Inches, feet, meters, miles, km, yards.
Weight Converter
Pounds, kilograms, grams, ounces, stones.
Temperature Converter
Celsius, Fahrenheit, Kelvin.
Password Generator
Strong random passwords, your length and rules.
Sleep Calculator
When to sleep (or wake) to align with 90-minute cycles.
Height Converter
Feet/inches ↔ centimeters.
Roman Numeral Converter
Number ↔ Roman, up to 3,999,999.
Countdown Calculator
Days, hours, minutes until any date.