Calculator Island
Free, simple calculators and converters for measurement, finance, cooking, fitness, and DIY projects.
Finance
Compound Interest
Calculate compound interest over time with different compounding frequencies.
Down Payment Calculator
Calculate how long it takes to save a down payment for a home purchase.
Mortgage Calculator
Calculate mortgage payments, total interest, and amortization.
Auto Loan Calculator
Calculate car loan payments and total interest over the loan term.
Measurement & Conversion
Inch Fraction Calculator
Convert from decimal inches to nearest inch fraction with a visual ruler.
Centimeter Calculator
Convert from centimeters to nearest fractional inch with a visual ruler display.
Feet to Fractional Tape Measure
Convert from decimal feet to nearest foot and inch fraction with visual tape measure.
Meters to American Tape Measure
Convert from meters to nearest foot and fractional inch with visual tape measure.
Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin temperature scales.
Time Converter
Convert between different time units from seconds to years.
Volume Converter
Convert between volume units like liters, gallons, cups, cubic feet, cubic yards, and cubic inches.
Distance Converter
Convert between distance units like miles, kilometers, feet, and meters.
Weight Converter
Convert between grains, grams, milligrams, kilograms, pounds, and ounces.
Triangle Calculator
Calculate hypotenuse and angles of a right triangle.
Nutrition & Fitness
BMI Calculator
Calculate your Body Mass Index and assess weight category.
Protein Intake Calculator
Calculate recommended protein intake based on weight and activity level.
Sleep Calculator
Calculate bedtime or wake-up time based on number of hours desired.
Kitchen Converter
Convert between common kitchen measurements like cups, tbsp, and ml.
DIY & Hobbies
Surfboard Volume
Calculate surfboard volume in liters based on dimensions and board type.
Surfboard Size Calculator
Find the right board volume for your weight, skill level, and fitness.
Aquarium Calculator
Calculate aquarium volume, weight, and other parameters.
Shoe Size Converter
Convert from inches or centimeters to US, EU, and UK shoe sizes.
Construction & Home Projects
Engineering & Technical
Hydrostatic Pressure
Calculate pressure exerted by a fluid such as sea water at depth.
Buoyancy Calculator
Calculate if an object will float or sink based on its shape, size, and density.
Ohm's Law
Solve for voltage, current, resistance, or power from any two known values.
Wire Gauge Calculator
Find the wire size needed for a given load, run length, and voltage drop limit.
LED Resistor Calculator
Size the series resistor an LED needs, with the nearest standard value.
Resistor Color Code
Read a resistor value from its colour bands, for 4, 5, and 6-band resistors.
Voltage Drop Calculator
Calculate voltage drop over a run of wire and check it against the 3% guideline.
Fun & Curiosities
Days Alive
Count how many days you have been alive, and when your next milestone lands.
Years Spent Sleeping
Work out how much of your life you have spent asleep.
Meals Eaten
Count the meals you have eaten in your life, and the time spent at the table.
Caffeine Calculator
Add up your caffeine per day and per year from how much you actually drink.