Everyday Calculators
Dates, time, grades, passwords and other everyday utility calculators.
Age Calculator
Calculate exact age in years, months and days from a birth date.
Bandwidth / Download Time Calculator
Calculate how long a file will take to download at a given connection speed.
Base64 Encode / Decode
Encode text to Base64, or decode a Base64 string back to text.
Bra Size Calculator
Estimate your bra size from band and bust measurements.
BTU Calculator
Estimate the BTU heating/cooling capacity needed for a room.
Concrete Calculator
Calculate how much concrete (in cubic yards and bags) you need for a slab.
Darts Scorer & Checkout Calculator
Play a live 501/301 game with running score, bust detection and checkout suggestions.
Date Calculator
Find the number of days between two dates, or add/subtract time from a date.
Day of the Week Calculator
Find out what day of the week any date falls on.
Density Calculator
Calculate density, mass or volume from the other two.
Dew Point Calculator
Calculate the dew point from temperature and relative humidity.
Dice Roller
Roll any number of virtual dice with any number of sides.
Electricity Cost Calculator
Calculate the running cost of an electrical appliance.
Engine Horsepower Calculator (Trap Speed)
Estimate engine horsepower from vehicle weight and quarter-mile trap speed.
Fuel Cost Calculator
Calculate the fuel cost for a trip.
Gas Mileage Calculator
Calculate your car's fuel economy (MPG) from miles driven and gallons used.
Golf Handicap Calculator
Estimate your golf handicap index from recent round scores.
GPA Calculator
Calculate your weighted grade point average from course credits and grades.
Grade Calculator
Calculate a weighted final grade from assignment scores and weights.
Gravel Calculator
Calculate how much gravel you need in cubic yards and tons.
Heat Index Calculator
Calculate the heat index (feels-like temperature in humid heat).
Height Predictor Calculator
Predict a child's approximate adult height from parents' heights.
Horsepower Calculator
Calculate horsepower from torque and engine RPM.
Hours Calculator
Calculate hours worked and pay, including overtime, from clock-in and clock-out times.
IP Subnet Calculator
Calculate network address, broadcast address and host range from an IPv4 address and CIDR prefix.
Love Calculator
A just-for-fun compatibility score between two names.
Mileage Reimbursement Calculator
Calculate business mileage reimbursement.
Molarity Calculator
Calculate molarity from moles (or mass) and solution volume.
Molecular Weight Calculator
Calculate the molecular weight of a chemical formula.
Mulch Calculator
Calculate how much mulch you need for a garden bed.
Ohm's Law Calculator
Solve for voltage, current or resistance using Ohm's Law.
Online Abacus
A real click-to-count abacus for learning place value.
Password Generator
Generate a strong random password with your choice of character sets.
Patio Calculator
Calculate the pavers and base material needed for a patio.
Random Number Generator
Generate one or more random numbers within a range.
Resistor Color Code Calculator
Decode a 4-band resistor color code into its resistance value.
Ring Size Converter
Convert between ring diameter, circumference and US ring size.
Roman Numeral Converter
Convert between numbers and Roman numerals.
Roofing Calculator
Calculate roofing squares and shingle bundles needed.
Shoe Size Conversion
Convert a US men's shoe size to US women's, UK, EU and centimeters.
Sleep Calculator
Find optimal bedtimes or wake times based on 90-minute sleep cycles.
Square Footage Calculator
Calculate the square footage of a room and an optional material cost.
Stair Calculator
Calculate the number of steps, riser height and stringer length for a staircase.
Tile Calculator
Calculate how many tiles you need for a floor or wall.
Time Calculator
Add or subtract two time durations (hours, minutes, seconds).
Time Card Calculator
Add up a week's daily hours and calculate pay with overtime.
Time Duration Calculator
Calculate the duration between two clock times.
Time Zone Calculator
Convert a time from one UTC offset to another.
Tire Size Calculator
Compare the overall diameter of two tire sizes.
URL Encode / Decode
Encode text for use in a URL, or decode a URL-encoded string.
Voltage Drop Calculator
Calculate voltage drop across a wire run for a given gauge and load.
Wind Chill Calculator
Calculate the wind chill (feels-like) temperature.