Other Calculators
Dates and time, construction, conversions, electronics, weather and fun tools. Every tool is free, runs in your browser and shows the formula behind the answer.
Date and Time
- Age CalculatorThis age calculator finds the exact time between a date of birth and any other date, in years, months and days, and in total months, weeks, days, hours, minutes and seconds.
- Date CalculatorUse this date calculator to count the days between two dates, or to find the date a given number of days, weeks, months or years before or after another date. Business-day options skip weekends.
- Time CalculatorThis time calculator adds and subtracts durations in days, hours, minutes and seconds, finds the date and time a given amount of time before or after a starting point, and evaluates time expressions.
- Hours CalculatorThis hours calculator counts the hours and minutes between a start time and an end time, and its second form finds the hours between two times on different dates.
- Time Card CalculatorThis time card calculator adds up the hours on a weekly timesheet from clock-in, clock-out and break times, and can work out regular and overtime pay.
- Time Zone CalculatorThis time zone calculator converts a date and time from one time zone to another, accounting for daylight saving time on that date, and lists the same moment in cities around the world.
- Time Duration CalculatorThis time duration calculator measures the time between two clock times to the second, and its second form measures the duration between times on two different dates.
- Day CounterThis day counter finds the number of days between two dates and shows how many are weekdays, weekend days and holidays, and its second form counts a number of days or business days from a date.
- Day of the Week CalculatorThis day of the week calculator tells you which weekday any date falls on, along with its day number in the year, its ISO 8601 week number and how many days remain in the year.
- Age Difference CalculatorThis age difference calculator finds the exact gap between two birth dates in years, months and days, and in total weeks and days, and shows each person's age on any date.
Housing/Building
- Concrete CalculatorThis concrete calculator estimates how much concrete a slab, wall, footing, column, tube, curb and gutter or set of stairs needs, in cubic yards, cubic feet, cubic meters and premixed bags.
- BTU CalculatorThis BTU calculator estimates the cooling capacity an air conditioner needs for a room or house, and its general-purpose form sizes heating or cooling from room volume and the temperature change you want.
- Square Footage CalculatorThis square footage calculator finds the area of common shapes in square feet, square meters, square yards and acres, and multiplies it by a price to estimate the cost of a project.
- Stair CalculatorThis stair calculator lays out a straight staircase from the floor-to-floor rise and the run, giving the number of risers and treads, their dimensions, the stair angle and the stringer length.
- Roofing CalculatorThis roofing calculator estimates the area of a roof from the house's base area, its pitch and the eave overhang, and converts any roof area into roofing squares and bundles of shingles.
- Tile CalculatorThis tile calculator works out how many tiles cover a floor or wall from the tile size, the area and the width of the grout joints, and converts the count into boxes and cost.
- Mulch CalculatorThis mulch calculator works out how much mulch you need in cubic yards, cubic feet, cubic meters and bags, from the area of your beds and the depth you plan to spread.
- Gravel CalculatorThis gravel calculator estimates how much gravel or sand a project needs by volume and by weight, from the area, the depth and the density of the material, and can price it per yard, ton or bag.
- Paint CalculatorThis paint calculator estimates how much paint a room needs from its dimensions or total wall area, after subtracting doors and windows, and converts the result into cans and cost.
Various Measurements/Units
- Height CalculatorThis height calculator estimates a child's adult height from their current growth and their parents' heights. Two smaller tools below give a parents-only prediction and convert heights between feet and centimeters.
- Conversion CalculatorPick a type of measurement, enter a value and choose the units to convert between. The conversion calculator also lists the value in every other unit of the same kind, from square feet and acres to liters and gallons.
- GDP CalculatorEnter the components of spending to calculate gross domestic product with the expenditure approach, or use the second tool to build GDP from incomes. The GDP calculator accepts any currency unit; the example figures are in billions.
- Density CalculatorPick the value you want, enter the other two and the density calculator does the rest, converting between metric and US units for density, mass and volume.
- Mass CalculatorEnter a density and a volume and this mass calculator multiplies them to give the mass, converting between more than 40 density units and 14 volume units along the way.
- Weight CalculatorEnter an amount and pick two units to convert between. This weight calculator covers metric, US and imperial units, from milligrams and carats to stone and tons, and shows the same amount in every other unit.
- Speed CalculatorChoose what to solve for, then enter the other two values. The speed calculator handles meters, kilometers, miles, nautical miles and more, and the converter below changes any speed between 26 units.
- Molarity CalculatorEnter any three of mass, molecular weight, volume and concentration and leave the fourth box blank. The molarity calculator converts between grams, moles, liters and concentration units such as M, mM, g/L and ppm.
- Molecular Weight CalculatorType a chemical formula, or pick a common chemical, and the molecular weight calculator adds up the standard atomic weights to give the molar mass and elemental composition. Brackets and hydrates are supported.
- Roman Numeral ConverterType a number such as 2026 or a Roman numeral such as MMXXVI and the Roman numeral converter translates it in either direction. The date converter below writes a full date in Roman numerals.
- Acreage CalculatorThis acreage calculator turns the length and width of a plot, or an area in any unit, into acres, hectares, square feet, square meters and more. Two extra tools handle irregular four-sided lots and boundaries given as corner coordinates.
Electronics/Circuits
- Voltage Drop CalculatorPick a wire, enter the circuit voltage, one-way length and load current, and the voltage drop calculator shows how many volts are lost along the run and what reaches the load.
- Resistor CalculatorPick the band colors to read a resistor's value and tolerance. The resistor calculator page also combines resistors in parallel and in series and works out the resistance of a length of conductor.
- Ohms Law CalculatorEnter any two of the four quantities and leave the other two boxes blank. The Ohm's law calculator works out the other two using V = I × R and P = V × I.
- Electricity CalculatorChoose a typical appliance or enter your own wattage and hours of use, then your electricity price per kWh. The electricity calculator estimates the energy used and its cost per day, month and year.
Internet
- IP Subnet CalculatorEnter an IP address and choose a subnet mask or prefix length. The IP subnet calculator returns the network and broadcast addresses, usable host range and every common representation of the address.
- Password GeneratorSet the length and character types, then press Generate. This password generator runs entirely in your browser and draws every character from the Web Crypto API's secure random number generator; nothing is sent or stored.
- Bandwidth CalculatorThis bandwidth calculator page has four tools: a data unit converter, a download and upload time estimate, a website bandwidth estimate from page views, and a converter between monthly data usage and connection speed.
- Base64 Encode / DecodePaste text to encode it as Base64, or paste Base64 to decode it back to text. This Base64 encode decode tool runs in your browser and supports UTF-8, UTF-16 and many legacy character sets.
- URL Encode / DecodePaste text or a link, choose encode or decode, and the URL encode decode tool converts it instantly using standard UTF-8 percent-encoding.
Everyday Utility
- GPA CalculatorThis GPA calculator works out your grade point average from letter grades and credits, combines it with past semesters for a cumulative GPA, and can plan the GPA you need to reach a goal.
- Grade CalculatorThis grade calculator works out a weighted average grade from percentages, points or letter grades, and shows what you need on the rest of the course, or on the final exam, to reach a target grade.
- Bra Size CalculatorMeasure around your bust and just under it, then enter both numbers. The bra size calculator gives your size in the main international systems; use it as a starting point for a fitting.
- Shoe Size ConversionPick adults, kids or infants, then enter a size in any one system, or leave the size boxes empty and enter your foot length. The shoe size conversion gives the matching size in every other system, including women's to men's.
- Tip CalculatorThis tip calculator shows the tip and total for a bill at the most common tipping percentages. The shared bill tool below splits the total, tip included, among everyone at the table.
- Golf Handicap CalculatorEnter your Handicap Index and the tees' ratings to find how many strokes you get on that course. The golf handicap calculator below it estimates your Handicap Index from up to 20 recent rounds under the World Handicap System.
- Sleep CalculatorThis sleep calculator suggests bedtimes or wake-up times that line up with complete 90-minute sleep cycles, and its second form finds a bedtime for any length of sleep.
Weather
- Wind Chill CalculatorEnter the air temperature and wind speed and the wind chill calculator returns how cold it feels on exposed skin, using the formula adopted by the US and Canadian weather services in 2001.
- Heat Index CalculatorEnter the temperature and the relative humidity, or use the second tool with the dew point, and the heat index calculator shows how hot it feels and the National Weather Service risk level.
- Dew Point CalculatorEnter any two of air temperature, relative humidity and dew point and leave the third box blank. The dew point calculator uses the Magnus formula and rates how muggy the air will feel.
Transportation
- Fuel Cost CalculatorEnter the trip distance, your vehicle's fuel efficiency and the price of fuel. The fuel cost calculator shows how much fuel the trip needs and what it will cost.
- Gas Mileage CalculatorFill the tank, note the odometer, and at the next fill-up enter both readings and the amount of gas you added. The gas mileage calculator returns your actual fuel economy and what each mile or kilometer cost.
- Horsepower CalculatorEnter a force, the distance it moves an object and how long that takes. The horsepower calculator works out the power, and the converter below changes between horsepower, watts and BTU per hour.
- Engine Horsepower CalculatorEnter the vehicle's weight, with driver, and either its quarter-mile time or its speed at the end of the quarter mile. The engine horsepower calculator estimates the power using two classic drag-racing formulas.
- Mileage CalculatorType two city names to get the straight-line mileage between them, plus rough estimates of the driving distance, driving time and flight time. The mileage calculator knows about 150 major US and world cities.
- Tire Size CalculatorEnter the three numbers from your tire's sidewall to see its real dimensions. The tire size calculator can also suggest sizes that keep the same overall diameter on a new wheel size, and compare two tires side by side.
Entertainment/Anecdotes
- Dice RollerChoose how many dice to throw and press Generate. The dice roller uses your browser's cryptographic random number generator, so every face is equally likely; the second tool rolls dice with any number of sides.
- Love CalculatorType two names and the love calculator turns them into a compatibility percentage. It is a game: the score comes from a fixed formula applied to the letters, so the same names always give the same result, and it says nothing real about a relationship.