Home, school and electrical calculators
Pick a calculator. Each shows the answer as you type, with the steps underneath.
Square footage calculatorTotal area of one or more rooms in square feet, square metres, yards and acres.Open the calculator ›Concrete calculatorConcrete needed for a slab, with waste allowance and number of bags.Open the calculator ›Mulch calculatorMulch needed to cover a garden bed to a chosen depth.Open the calculator ›Gravel calculatorGravel for a driveway or path, in cubic yards and tons.Open the calculator ›Paint calculatorGallons of paint for a room from its size, doors, windows and coats.Open the calculator ›Tile calculatorNumber of tiles and boxes for a floor or wall, with a waste allowance.Open the calculator ›Cubic yard calculatorVolume in cubic yards from length, width and depth in any unit.Open the calculator ›Cubic feet calculatorVolume in cubic feet from length, width and height in any unit.Open the calculator ›Ohm's law calculatorFind voltage, current, resistance and power from any two of them.Open the calculator ›Watts to amps calculatorCurrent in amps from power in watts, for DC, single phase and three phase.Open the calculator ›Amps to watts calculatorPower in watts from current in amps, for DC, single phase and three phase.Open the calculator ›Volts, amps and watts calculatorFind watts, amps or volts from the other two.Open the calculator ›Electricity cost calculatorWhat a device costs to run per day, month and year.Open the calculator ›Voltage drop calculatorVoltage drop over a wire run from AWG size, length and current.Open the calculator ›Gas mileage calculatorMiles per gallon and litres per 100 km from distance and fuel used.Open the calculator ›Fuel cost calculatorFuel needed and what a trip costs from distance, mpg and fuel price.Open the calculator ›Speed, distance and time calculatorFind speed, distance or time from the other two.Open the calculator ›Tire size calculatorDiameter, circumference and speedometer error between two tire sizes.Open the calculator ›Recipe scalerScale ingredient quantities up or down for a different number of servings.Open the calculator ›GPA calculatorGrade point average from your courses, grades and credit hours.Open the calculator ›College GPA calculatorYour new cumulative GPA after this term's grades.Open the calculator ›Weighted grade calculatorYour overall grade when assignments count for different percentages.Open the calculator ›Final grade calculatorThe score you need on the final exam to reach the grade you want.Open the calculator ›Subnet calculatorNetwork, broadcast, mask and usable hosts for an IPv4 address and prefix.Open the calculator ›Password generatorStrong random passwords made in your browser, never stored or sent.Open the calculator ›
Home, school and electrical calculators
- Square footage calculator
- Concrete calculator
- Mulch calculator
- Gravel calculator
- Paint calculator
- Tile calculator
- Cubic yard calculator
- Cubic feet calculator
- Ohm's law calculator
- Watts to amps calculator
- Amps to watts calculator
- Volts, amps and watts calculator
- Electricity cost calculator
- Voltage drop calculator
- Gas mileage calculator
- Fuel cost calculator
- Speed, distance and time calculator
- Tire size calculator
- Recipe scaler
- GPA calculator
- College GPA calculator
- Weighted grade calculator
- Final grade calculator
- Subnet calculator
- Password generator
Method: standard arithmetic shown step by step; no outside data is used. Checked 2026-11-12.
Written by Calculators Free Editorial Team · Data checked 2026-11-12
About · How we verify this · Editorial policy · Corrections
About · How we verify this · Editorial policy · Corrections
General information only. Results are plain arithmetic on the numbers you enter; check anything important (money, health, school work) against your own records or the official source.