Step 1) Determine the Voltage Rating

Look for the AC voltage rating of your electric item. Voltage rating is often stated on the specification side of the item or on its power supply adapter and it is indicated with a "V" or "VAC".

Your item's voltage rating should fall within these three groups:

also know as Dual Voltage

120V or 110-125V

230V or 220-240V

Step 2) Determine the power requirement of your item (WATT)

Now that you know that your item requires a voltage converter or transformer, you'll need to find the WATT (W) or the AMP (A) rating to determine the correct size voltage converter. As shown in the step 1 above, look for this information on the specification sheet of your item.


220V - 500mA

240V - 1.8A

Step 3) Purchase the correct size voltage transformer

Now that you know your items' Voltage and Watt ratings we can determine the correct voltage converter or transformer for your item. All of our heavy duty transformers are designed for continuous use and function as step up and step down transformers. Electronics items often surge or spike when they are switched on causing the wattage ratings to exceed the specification sheets. Thus, it is always best to purchase a transformer larger than your items required wattage to handle any power surges that may occur. The best way to figure out which transformer to purchase is by multiplying the wattage rating of your item times the efficiency factor of the transformer you select.

Efficiency factors of all the transformers that we sell:

E-Factor 1.25 1.5 2.0 2.5
Transformer Model LiteFuze convertingbox LiteFuze VT series LiteFuze LR series Seven Star TC series Seven Star ST Seven Star AR Seven Star THG

E.Factor x Watt of your item = Min. Watt required of the corresponding E. factor transformer

You Can Calculate your Min. Watt required


Example, if your item is 150W:


= 187.5W

LiteFuze convertingbox 200


= 225W

LiteFuze VT-300


= 300W

LiteFuze LR-500 or Seven Star TC-300


= 375W

Seven Star ST-500 or Seven Star AR-500

*Lower efficiency factor equals the better quality of the voltage transformer.

Why is the LiteFuze convertingbox the most recommended and top selling transformer?

Can I use U.S 125V Power strips or Surge Protectors with voltage transformer to connect multiple items?

No, the way U.S. power strips or surge protectors are configured they will burn out when used it a transformer even when output is at 110V. We recommend the 250V power strips to use with voltage converters. The 250V universal power strips will work on any voltage and accept any type of plugs.

Need help or have more questions?

Call us at 847-983-4761 or read our voltage converter guide.

If your item is rated 100-240V then it is dual voltage and its designed to operate on any voltage without a voltage converter or a voltage transformer. You'll just need a correct adapter plug for the country you want to use it in. Plug adapters are listed here.

Items rated at 110-125V require a step down voltage converter or voltage transformer for use in 220-240V countries. Proceed to step 2 to determine which voltage converter.

Items rated at 220-240V require a step up voltage converter or voltage transformer for use in 110-120V countries. Proceed to step 2 to determine which voltage converter.

*Fairly simple, as 'W' is clearly stated in this case 23W. Proceed to step 3.

Calculate W = V x A, and 1000 mA is 1A so in this case 220V x 0.50A = 110W. Proceed to step 3.

Calculate W = V x A, so in this case 240V x 1.8A = 432W. Proceed to step 3.
*Note you may find a range of wattage rating, i.e 1200W - 2000W on an item so in that case select the MAX wattage rating.

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