How Many Amps Is 10 kVA at 120V?

A 10 kVA single-phase load at 120V draws 83.33 amps. On three-phase, the same kVA spreads across three conductors, so each line carries only 27.78A. At a load power factor of 0.8 the load's real-power draw is 8 kW (a generator or UPS feeding this load has a separate kW rating set by the manufacturer which must be checked independently against the kVA rating).

10 kVA equals 83.33 amps at 120 volts (single-phase)

83.33 Amps

Three Phase (120V L-N, 208Y/120)27.78 A

Try: 7.5kVA at 120V 5kVA at 120V 15kVA at 120V 3kVA at 120V

kVA

Volts

Amps (1Φ)

83.33

Assumes a single-phase AC circuit at the input voltage. kVA is apparent power, so no power factor term is involved.

Formulas

Single Phase

I_(A) = (kVA × 1000) ÷ V

(10 × 1000) ÷ 120 = 10,000 ÷ 120 = 83.33 A

Three Phase (120V Line-to-Neutral)

I_(A) = (kVA × 1000) ÷ (3 × V_L-N) ≤ equivalent to (kVA × 1000) ÷ (V_L-L × √3)

10,000 ÷ (3 × 120) = 10,000 ÷ 360 = 27.78 A

Applies to 208Y/120 systems where 120V is the line-to-neutral voltage (line-to-line ≈ 207.84V).

Single Phase vs Three Phase

The same 10 kVA unit draws very different current depending on the phase configuration:

Configuration	Formula	Current at 120V
Single Phase	10,000 ÷ 120	83.33 A
Three Phase (120V L-N)	10,000 ÷ (3 × 120)	27.78 A

For this specific case, 10 kVA at 120V, three-phase carries about 66.67% less current per line than single-phase at the same voltage. That gap tracks the 1 ÷ √3 factor for L-L three-phase (or 1 ÷ 3 for L-N), which is why three-phase distribution is common at commercial and industrial scale: the same apparent power rides on smaller conductors and smaller breakers (applies to 208Y/120 systems).

Generator & UPS Sizing

Load-Side Real Power by Power Factor

A load with an apparent power of 10 kVA draws different amounts of real power depending on the load's own power factor. The table below is a load-side conversion, not a forecast of what a generator or UPS will output for that load: generators and UPS units publish their own independent kW rating set by the engine or inverter design, and that rating is often lower than kVA × the load's PF.

Load Type	Load PF	Load Real Power (kW)	Current at 120V
Resistive (heaters, lights)	1.0	10 kW	83.33 A
Mixed typical	0.85	8.5 kW	83.33 A
Motors/HVAC	0.80	8 kW	83.33 A
Computers/servers (no PFC)	0.65	6.5 kW	83.33 A

Note: current draw stays the same across the rows because kVA sets the current, not the load's power factor. PF only affects how much real work (kW) the load does per amp drawn.

Sizing a load against a source. If you are feeding this load from a UPS, generator, or transformer, check the load against both the source's kVA rating AND the source's kW rating. Those are two independent numbers published by the manufacturer. A 10 kVA / 8 kW generator, for example, can supply up to 10 kVA of apparent power AND up to 8 kW of real power, whichever limit is reached first. Do not use the kW figures above as a substitute for the source's published kW rating.

Circuit Sizing: Starting Points

The numbers below are rough order-of-magnitude starting points under typical assumptions (copper conductors, 75°C terminations, short run, no ambient or bundling derates, non-continuous duty). They are not install specs. Actual breaker and wire selection depends on the equipment nameplate, conductor and termination temperature ratings, cable type, run length and voltage-drop target, ambient and bundling conditions, whether the load is continuous, any NEC 430/440 motor or HVAC provisions, and local code.

	Single Phase	Three Phase
Current draw (at full kVA)	83.33 A	27.78 A
Ballpark branch OCP	~90A	~30A

For a real install, run the full wire-size calculator with your actual run length, voltage, and drop target, and verify breaker selection against the equipment nameplate and local code.

Energy Cost at Full Load

A load with an apparent power of 10 kVA at load PF 0.85 draws 8.5 kW of real power. Running cost at that draw: $1.45/hour at $0.17/kWh (rates last reviewed April 2026), or $346.80/month (8h/day). Full breakdown.

kW Equivalent

10 kVA at PF 0.85 = 8.5 kW. See 8.5 kW to amps at 120V.

Other kVA Ratings at 120V

kVA	Single Phase Amps	Three Phase Amps (L-N)	Real Power (PF 0.8)
1 kVA	8.33 A	2.78 A	0.8 kW
2 kVA	16.67 A	5.56 A	1.6 kW
3 kVA	25 A	8.33 A	2.4 kW
5 kVA	41.67 A	13.89 A	4 kW
7.5 kVA	62.5 A	20.83 A	6 kW
10 kVA	83.33 A	27.78 A	8 kW
15 kVA	125 A	41.67 A	12 kW
20 kVA	166.67 A	55.56 A	16 kW
25 kVA	208.33 A	69.44 A	20 kW
30 kVA	250 A	83.33 A	24 kW
40 kVA	333.33 A	111.11 A	32 kW
50 kVA	416.67 A	138.89 A	40 kW

Frequently Asked Questions

How many amps is 10 kVA at 120V?expand_more

10 kVA at 120V is 83.33 amps (single-phase) or 27.78 amps (three-phase (208Y/120)).

Can a 10 kVA generator run my whole house?expand_more

A 10 kVA unit can cover most residential loads but often struggles with central AC plus other large appliances running simultaneously. Capacity depends on inrush from compressors and motors, load sequencing, and any transfer-switch load management. An electrician can run a load calc to confirm.

How much fuel does a 10 kVA generator use?expand_more

Fuel burn is set by the generator's specific-fuel-consumption curve, not a rule of thumb tied to the kVA rating. It varies sharply with fuel type (gasoline vs diesel vs natural gas vs propane), load percentage (partial-load efficiency is much worse than full-load), engine size and age, altitude, and ambient temperature. For a specific unit, check the manufacturer's fuel-consumption curve at your expected load percentage. Generic per-hour estimates from the kVA rating alone are not reliable enough to plan fuel capacity from.

What size generator do I need for my loads?expand_more

Generator sizing is not a single-formula calculation. A rough napkin pass is: add up the steady-state watts of everything you plan to run, divide by a planning power factor (often 0.8 but not universal), and add margin. Then cross-check the result against the generator's published kW rating, which is a separate manufacturer spec set by the engine (prime mover) and is not derived from the generator's kVA rating by any formula. The caveats that matter for a real install: motor and compressor inrush can be several times steady-state current, load diversity and sequencing affect peak demand, voltage-dip tolerance of sensitive equipment limits how much motor load a given genset can start, and altitude and ambient temperature both derate output. A load with an apparent power of 10 kVA at PF 0.8 has a real-power draw of 8 kW, but that number alone is not sufficient to size a generator for a real installation.

What is the difference between kVA and kW?expand_more

kVA is apparent power (V×I), which sets the current on the circuit and the sizing of conductors, breakers, and windings. kW is real power (the portion that does useful work), equal to kVA×load PF. A load with an apparent power of 10 kVA at load PF 0.8 draws 8 kW of real power. For a source such as a generator or UPS, kVA and kW are two independent manufacturer ratings, not two views of the same spec, and both have to be checked when sizing a load.

This calculator provides estimates for reference purposes only. Always consult a licensed electrician and verify compliance with the National Electrical Code (NEC) and local electrical codes before performing any electrical work.