Every power and electronics calculator you need, in one place

Find out exactly what an appliance adds to your electricity bill — per hour, per day, per month and per year.

Estimate how long a portable power station, solar generator or 12 V battery will run a fridge, CPAP, laptop or anything else — or find the battery size you need.

Size a solar system from your electricity bill: system kW, number of panels, roof area, cost and payback period, and an off-grid battery bank.

Convert battery capacity between mAh and Wh, check airline carry-on limits and see how many phone charges a power bank really gives.

Check voltage drop over a cable run and find the smallest wire gauge that keeps it within limits — for cars, RVs, boats, solar and home circuits.

See how long your electric car takes to charge, what it costs, how much range you add and how much you save compared with gas.

Pick the band colors to read a resistor’s value, tolerance and temperature coefficient — or type a value to get its color bands.

Enter any two values and get the other two instantly. Type values like 4.7k, 20m or 3.3.

Get the right current-limiting resistor for your LEDs, rounded to a standard value, with the wattage rating you need.

Find the output of a resistor divider, or the resistor you need for a target voltage, including the effect of a load.

Find the cutoff frequency of an RC low-pass or high-pass filter — or the R or C you need — plus gain and phase at any frequency.

Convert between decimal, hex, binary and octal at any bit width — signed or unsigned — and copy ready-made Verilog, VHDL and C literals.