Question 1

How do you convert volts to amps?

Accepted Answer

You cannot convert voltage to current directly — they measure different things. You need one more quantity. With resistance, Ohm's law gives amps = volts ÷ ohms. With power, amps = watts ÷ volts (divide again by power factor on AC, and by 1.732 × volts for three-phase). Example: 120 V across 10 Ω draws 12 A.

Question 2

How many amps is 120 volts?

Accepted Answer

There is no single answer — 120 V is the supply voltage, not a load. A 60 W bulb on 120 V draws 0.5 A; a 1,500 W space heater on the same 120 V draws 12.5 A. The current depends entirely on what is plugged in.

Question 3

Does higher voltage mean more amps?

Accepted Answer

For a fixed resistance, yes — doubling the voltage doubles the current. For a fixed power rating the opposite holds: the same 1,500 W draws 12.5 A at 120 V but only 6.25 A at 240 V. That is why large appliances and EV chargers are wired at 240 V — the same power moves through less current and therefore smaller conductors.

Question 4

Can I pick a breaker from this number?

Accepted Answer

It gives you the code-minimum starting point from NEC 240.6 and Table 310.16 (75°C copper), including the 125% rule for loads that run three hours or more. Real installations also account for termination temperature under 110.14(C), conductor bundling, ambient derating, and voltage drop. Have a licensed electrician confirm the design with your local AHJ.

Volts to Amps Calculator

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