FREE CALCULATOR
Concrete Calculator
Estimate slabs, footings, columns, curbs, and solid stairs, including voids and waste.
Open Concrete CalculatorFREE TOOLS · NO ACCOUNT NEEDED
Calculators
for the work ahead.
Choose a calculator, enter your dimensions, and get a clear estimate.
FREE CALCULATOR
Voltage Drop Calculator
Estimate cable voltage drop for DC, single-phase AC, or balanced three-phase AC circuits.
Open Voltage Drop CalculatorFREE CALCULATOR
Resistor Calculator
Read resistor color bands or calculate the equivalent resistance of two resistors.
Open Resistor CalculatorFREE CALCULATOR
Ohm’s Law Calculator
Enter two known values to calculate voltage, current, resistance, and power.
Open Ohm’s Law CalculatorFREE CALCULATOR
Electricity Calculator
Estimate electricity consumption and energy cost for an appliance or group of identical devices.
Open Electricity CalculatorFREE CALCULATOR
Square Footage Calculator
Measure common shapes, subtract openings, and compare areas in square feet and square metres.
Open Square Footage CalculatorFREE CALCULATOR
Mulch Calculator
Estimate mulch volume, bags, and cost for your next landscape project.
Open Mulch CalculatorFREE CALCULATOR
Gravel Calculator
Calculate gravel volume and estimated weight using your supplier’s bulk density.
Open Gravel CalculatorFREE CALCULATOR
Trench Volume Calculator
Estimate excavation volume for rectangular or sloped trenches, and allow for excavated soil swell.
Open Trench Volume CalculatorFREE CALCULATOR
Roofing Calculator
Estimate pitched roof area, roofing squares, and material coverage.
Open Roofing CalculatorFREE CALCULATOR
Tile Calculator
Plan straight-grid tile layouts, whole-tile quantities, and boxes.
Open Tile CalculatorFREE CALCULATOR
Stair Calculator
Explore uniform stair rise, tread count, total run, and incline.
Open Stair CalculatorFREE CALCULATOR
BTU Calculator
Estimate room air-conditioner cooling capacity from floor area and room use.
Open BTU Calculator