Home & Construction calculators
Free home and construction calculators: NEC wire size, cubic yards of dirt, gravel and mulch, renovation cost, cubic and linear feet, and weight per gallon.
Wire Size Calculator (Amps to AWG)
Find the right wire gauge for 20, 30, 40, 50, 100 amp circuits. Uses NEC 310.16 ampacity, copper or aluminum, with voltage drop check and full amp chart.
Weight per Gallon Calculator
How much does a gallon of water, diesel, gasoline, propane, milk or paint weigh? Convert any volume to pounds and kilograms.
Linear Feet Calculator
Convert inches, meters or square feet to linear feet, add up multiple pieces, and estimate cost per linear foot for boards, trim, fencing and countertops.
Cubic Feet Calculator (ft³)
Calculate cubic feet for a box, room, cylinder, sphere or cone from inches, feet, yards or meters, and convert to cubic yards, liters and gallons.
Current Divider Calculator (Parallel Resistors)
Split a total current across two or more parallel resistors: branch currents, equivalent resistance and voltage, using the standard current divider rule.
Renovation Cost Calculator: Bathroom, Kitchen, Lighting
Estimate bathroom and kitchen renovation costs from 2025 national and regional averages, scaled to your room, or price a lighting job with your own quotes.
Cubic Yard Calculator: Dirt, Gravel & Mulch
How many cubic yards of dirt, gravel, topsoil or mulch you need for an area and depth, plus tons, bags per yard and truckloads.